I got the master cyl from autozone. They had the part # of 1371.

But it did not list it as a disc or drum set up. I went ahead and got it. I noticed the front tank is a lot bigger than the back.

Is that how it is on your guys jeeps with the same mast cyl?

It does have the #5470408- 1 1/8 on the bottom of it.

I havent installed it yet I was gonna wait and see if this was the right one. I also got the wilwood porportioning valve like I was told to.


I was always under the understanding that the tanks where to be the same size for a 4 wheel disc set up.

thanks for your help.

I cant remeber if mine were the same size or not,

But there are pictures here

http://wheelingpiazzas.com/pictures/brakes/DCP00552.JPG

http://wheelingpiazzas.com/pictures/brakes/DCP00553.JPG

Yeah mine doesnt even come close to looking like that. Mine looks more like a truck style. its friggen huge and it has a massive front resivoir and a tiny rear one ( Closest to the firewall).

The flare fitting i noticed was screwed up on mine so i took it back, i am trying another place tomarrow and see if they have the correct one.

thanks for the pics.

piazza where did you buy yours mine doesn't look anything like that. I haven't installed it yet and i was just wondering so i can go replace mine and buy one like this but autozone only had one like I got. no number on the bottom and the resivoirs are the samesize. help i need brakes!

I took mine back and went to Parts America and they have the correct one for $4 cheaper. It looks just like piazza's

Friggen nice!

I got mine from a place called all parts auto here in the bay area.

Looks like autozone has em.

Whats the deal with these masters? I am interested, my brakes
suck!

The master Cylinder is one that is proven to work with Manual 4 wheel discs.

It has an 1 1/8 bore so it moves alot of fluild, and is a direct bolt up to a CJ(except the shaft)

It was designed for a 68 covette with 4 wheel discs and manual or power brakes.

Steve

Originally posted by WheelingPiazza
The master Cylinder is one that is proven to work with Manual 4 wheel discs.

It has an 1 1/8 bore so it moves alot of fluild, and is a direct bolt up to a CJ(except the shaft)

It was designed for a 68 covette with 4 wheel discs and manual or power brakes.

Steve

What needs to be done to make the shaft match up? Pics of that?

Basiclly what I did was take the old shaft(push rod) measured the travel to the back of the piston, Marked the difference, took it down to my local parts store went thru about 10 and found one that I could cut down.

This is the first i have heard of any midification to the rod. Which one did you use and what measurement did you cut it down to?

Piazza the one i got from autozone did not look anything like yours and like i said the tanks are equal in size. I would like as much info as possible because my jeep isn't gong anywhere until i get some brakes on it!
thanks

The rod I started with was the stock 74 cj rod, Then I went and got a one that end matched up to mine but was to long and I cut it down,

When you do this make sure you measure your travel on the pedal, Make sure the travel goes all the way to the floor.. ITs sounds scarier then it is..

Yeah thats the first time I heard we had to have a different shaft for the master cyl.

Bummer because now I am 1hr away from any decent auto stores and had planned on this being tonights project.

Hey Piazzas, Maybe you ought to yank yours out and give us the measurement of the rod.




Man, bummer, real bummer.

Try your old one it might work, I am just saying for my application I had to have a 1/4 longer..

I can measure the old one and give you the lenght tonight if I remeber

Hey Dennis what was the part # for that I have been looking to do the same thing. The shaft is really no big deal all u have to do is measure your pedal stroke and the length of the push and place the rod acordingly. if the hole is to big or to little cut your old one off and weld it on and then sleave it. That is one thing u don't want to break.

hey any of you have it bolted up to a power booster? I just set up the YJ with front d44 RC bigger brakes obviously and rear 9" with disc. The breaks alomost go to the floor then stop. With the D30 in the front and the 9" in the rear the master was fine. But the bigger front disc kick its little ass. I have this in a 95 YJ, any suggestions would be great :beer:

BlueYJ

Dennis,

I looked up the corvette master on Autozone.com and the 1371 is for manual brakes, the #1372 they show for Power brakes maybe that is the one you need. If you do get it let us know if the front and back bowls are equal sizes.

BlueYJ

I did get the one for the Manual brakes but it most certainly wasnt for a vette. I doubt if that sucker would even fit under the hood of one!

There must have been a screw up at the factory. The front bowl was 2.5 times bigger than the rear bowl. I ended up going with parts America for the correct master cyl.

Its is Identical to the one Piazza has shown here.

The front and rear bowl on the parts America one are darn near the same front and rear.


My Jeep is a 1973 so the spec for yours piazza should be the same as mine. Please try and get us a length of the rod.

Big thanks to Piazza for doing the experamental work on this set up!

I didn't use the corvette cylnder sice I still have the drums on the rear of 14 bolt, so I went with a ton chevrolet cylinder....anyway on mine I had to shorten the rod so I went by the local hot rod barn and picked up a threaded clutch rod for a chevrolet car (had the proper end on it for the master cylinder, then cut it down about an inch and cut my origonal rod off short and used a die to run 3/8 thread on the short rod, then used a 1.5 in long tube nut (like that used on all thread) and screwed the two rods together with a jam nut to make my own adjustable rod, cost me $10 but if I change out cylinders I can adjust the rod to fit.

hope it helps,
Justin

Sorry I forgot about doing this but

the stock rod is 5 1/8th inches

I added another 1/2 inch to it.

Hope that helps

can an adjustable rod be purchased????

yep or you can make one.

the rod i have is about 3 inches and it fits really far down into the piston in the master cylinder I am not sure if theis is the right setup but I dont think that my stock rod caomes even close to 5 inches.

Originally posted by BlueYJ
hey any of you have it bolted up to a power booster? I just set up the YJ with front d44 RC bigger brakes obviously and rear 9" with disc. The breaks alomost go to the floor then stop. With the D30 in the front and the 9" in the rear the master was fine. But the bigger front disc kick its little ass. I have this in a 95 YJ, any suggestions would be great :beer:

BlueYJ

Yeah, I used this MC in a 93 YJ. The MC wouldn't bolt up directly, I had to take a grinder to it and trim down the outside of the mounting surface to make it fit into the recessed surface of the stock power booster.

The rod needs to be lengthened about 2/10th of an inch also.

Works like a charm with Waggy calipers in front and Cadilac Calipers in the rear.

So isley,

You used the 1372 MC out of a 68 Corvette? how did you lengthen the rod? Thanks.

BlueYJ :cool2:

It appears to be the same MC as the one in the pics above. It is for the same application mentioned. I bought it at NAPA, not sure of the part number for it. I can get it if you want though.

The rod is threaded and I was able to unscrew it enough to make the length work.

wheelin pizzaz-I saw on one of your posts your rod was 5 1/8" and you added 1/2 inch to it.is that the measurement from end to end or the end to the begining of the circle for the pedal attachment?Ive got 2 jeep rods and one is 5-1/8 end to end and one is 5-5/8.thanks-todd

End to end..

Adding the 1/2" end to end worked for me on my '73 pushrod too.

Any of you guys who did the 4 wheel disc swap, are you still using your porp valve or did you delete it and t-block Fronts and Rears out?
I know that Navajo booster kit reccomends ditching the porp valve.

These are the two numbers I have for Vette power masters;
raybestos mc39018 $78 new
m 1372 $35 rebuilt
PepBoys price.

I deleted mine. I am still having issues trying to fill the front 60 calipers, but the rear calipers work great.

Originally posted by JeepinDoug
Any of you guys who did the 4 wheel disc swap, are you still using your porp valve or did you delete it and t-block Fronts and Rears out?
I know that Navajo booster kit reccomends ditching the porp valve.

These are the two numbers I have for Vette power masters;
raybestos mc39018 $78 new
m 1372 $35 rebuilt
PepBoys price.


I couldn't tell you about the porp valve yet I just got the master cyl yesterday going in tomorow, but I plan on trying it 1st w/the porp valve in.

the # I got is M1371 I think that the M 1372 is for the power steering master if I am not mistaken

Originally posted by kcpsg
I think that the M 1372 is for the power steering master if I am not mistaken

Ah yea.........That's what I said,
"two numbers I have for Vette power masters"

Originally posted by JeepinDoug


Ah yea.........That's what I said,
"two numbers I have for Vette power masters" :bounce: :laughing: :bounce2: (Sorry Phil :flipoff2: )

But to add my.02, I am using the power version of this MC (29969 stamped into the side), D44 with the D30 brakes up front and Explorer discs out back and my brakes SUCK. I think it has to do with the 1 1/8" bore not providing enough pressure. It has PLENTY of volume, but a smaller bore M/C would provide more pressure since the caliper bores are relatively small. I have to stand on it to get any brakes. My plan is to swap to 1/2 ton brakes up front and see if that helps since those are much larger calipers.

[QUOTE]Originally posted by shelljeep
[B]:bounce: :laughing: :bounce2: (Sorry Phil :flipoff2: )



:bounce: :flipoff2: :bounce2: back @ ya Shell:D

I run the 29969, no prop valve, 3/4 ton d44 up front, 14 bolt out back and 38.5 tsl/sx tires and mine stops on a dime. Most around here run the 1 1/8 bore and have no problems. I think everyone runs the front bowl to the rear brakes and rear bowl to front brakes (some have had soft brakes when not doing it this way.)

Im finishing this today so Ill give you my results soon.t

I went with the 1977 vette. It has the shallow hat for the push rod. No mods were needed at all to bolt it up.
This was on a 81 cj with stock power brakes.

Ill note that for future ref-thanks.todd

Here are two links that I found very useful when designing my brake system. The mark williams page has an excellent calculator to determine the amount of pedal pressure required in order to get X amount of line pressure.

http://www.hotrodheaven.com/tech/brakes/brakes6.htm

http://www.markwilliams.com/technical/pedalRatio.html

I ended up going with a 1" master cylinder from a chrysler. I found that was the best compromise between pedal effort and pedal movement.

Will the 68' vette MC bolt up to a hydroboost system? Would be a nice addition to a power brake MC.
- Zach

The 68 MC will bolt to an early 80's Buick style hydroboost.

Thats what I run.

Originally posted by Meyer
I run the 29969, no prop valve, 3/4 ton d44 up front, 14 bolt out back and 38.5 tsl/sx tires and mine stops on a dime. Most around here run the 1 1/8 bore and have no problems. I think everyone runs the front bowl to the rear brakes and rear bowl to front brakes (some have had soft brakes when not doing it this way.)

Your brakes stop well because the MC bore is better matched to the calipers' bores due to your use of the larger brakes. If you use this MC with the smaller stock Jeep CJ brakes, you will not get the same results.

The stock CJ brake fittings require you to reverse the lines with this Vette MC compared to what they were on the stock MC. Otherwise, you will have to use adapters. With lines reversed for 29969, the front bowl feeds the front brakes, rear bowl feeds rear brakes. Meyer, are you saying that the bowls are proportioned differently from one another?

Originally posted by "D"
I got the master cyl from autozone. They had the part # of 1371.

But it did not list it as a disc or drum set up. I went ahead and got it. I noticed the front tank is a lot bigger than the back.

Is that how it is on your guys jeeps with the same mast cyl?

It does have the #5470408- 1 1/8 on the bottom of it.

I havent installed it yet I was gonna wait and see if this was the right one. I also got the wilwood porportioning valve like I was told to.


I was always under the understanding that the tanks where to be the same size for a 4 wheel disc set up.

thanks for your help.




I had just got my 1371 the other day, and it looked like the one piazza has in the pic, but after putting it on I was unable to get any fluid flow to the rear brakes, I took it off and bench bled it and re installed it. still not working. So I returned it and got another 1371 and it looked almost like the original MC w/one large and one small resevoir but much larger. I was going to return it but in the fine print in the instructions it says that it is still a 1371 and guarenteed to work as intended. I have yet to put it on though, I have some other braking issues that I need to take care of, such as removing the prop valve. It is keeping too much pressure on the rear brakes.

Shell, I am not sure about the bowls being proportioned differently. I know my comment infers that. My comment comes from reading alot of posts before I did the swap. Several people mentioned they had no brakes and when they setup the bowls/lines like I mentioned, it worked fine. There were alot of stories of bench bleeding 5 times, installing new lines, etc... you get the picture. I set it up that way and it has been fine. Your comment about the CJ brakes makes sense. I run the 3/4 ton GM calipers on all corners.

Originally posted by shelljeep
:bounce: :laughing: :bounce2: (Sorry Phil :flipoff2: )

But to add my.02, I am using the power version of this MC (29969 stamped into the side), D44 with the D30 brakes up front and Explorer discs out back and my brakes SUCK. I think it has to do with the 1 1/8" bore not providing enough pressure. It has PLENTY of volume, but a smaller bore M/C would provide more pressure since the caliper bores are relatively small. I have to stand on it to get any brakes. My plan is to swap to 1/2 ton brakes up front and see if that helps since those are much larger calipers.

I run chevy 3/4 ton fronts and rear, The calipers are bigger and I dont have a problem with my brakes running 36s and 38s.

It sounds like you have your lines swapped.

Originally posted by WheelingPiazza


I run chevy 3/4 ton fronts and rear, The calipers are bigger and I dont have a problem with my brakes running 36s and 38s.

It sounds like you have your lines swapped.

Just can't let this thread die w/o adding:

Piazza & Meyer,
I swapped to 1977 GM 1/2 ton/3/4 ton calipers(same piston diameter, I checked) in the front(can't do that in the rear-running dual beadlox), & that improved my pedal slightly. Very slightly. I still can't get the front to lock up, but the rear brakes would still almost lock up right at the last moment. I know my lines, MC are bled properly. Soo...

I got the fittings and reversed my lines today, bled and leak-checked... no difference whatsoever.:( So much for the quick fix.

I suspect this 29969 MC might be a poor choice for use with powerbrakes. I guess it is the hot ticket for those of you with manual brakes, but I can't get it to work for me.

Jeepin' Doug-did you ever get your power setup using the 29969 to work properly? I saw you were asking about the prop valve earlier, you wouldn't be asking questions if your chit was working right, would you?

The '79 Firebird MC that is another favorite is the same bore (1 1/8") as the Vette, so I don't think it will help either. The stock MC for this '83 CJ is 1" bore, the '78 MC for the CJ is 1 1/16", so I might try one of them next I guess. If those don't work, than there is the GM dual vacuum booster swap. I don't know.

Sorry for the Hijack.

Originally posted by shelljeep


Just can't let this thread die w/o adding:

Piazza & Meyer,
I swapped to 1977 GM 1/2 ton/3/4 ton calipers(same piston diameter, I checked) in the front(can't do that in the rear-running dual beadlox), & that improved my pedal slightly. Very slightly. I still can't get the front to lock up, but the rear brakes would still almost lock up right at the last moment. I know my lines, MC are bled properly. Soo...

I got the fittings and reversed my lines today, bled and leak-checked... no difference whatsoever.:( So much for the quick fix.

I suspect this 29969 MC might be a poor choice for use with powerbrakes. I guess it is the hot ticket for those of you with manual brakes, but I can't get it to work for me.

Jeepin' Doug-did you ever get your power setup using the 29969 to work properly? I saw you were asking about the prop valve earlier, you wouldn't be asking questions if your chit was working right, would you?

The '79 Firebird MC that is another favorite is the same bore (1 1/8") as the Vette, so I don't think it will help either. The stock MC for this '83 CJ is 1" bore, the '78 MC for the CJ is 1 1/16", so I might try one of them next I guess. If those don't work, than there is the GM dual vacuum booster swap. I don't know.

Sorry for the Hijack.

I haven't made the swap yet. I have an 8.8 ready for the rear and a 1/2 ton D44 I'm working on for the front so I'm still collecting info on the swap. I'll be using the CJ booster with the power master 29969 and ditching the porp valve. The 8.8 has a small rear caliper piston. All the info I've read so far leads me to this combo for me. The variable changes quickly for guys running the former front calipers in the rear, being the pistons are larger.
U_SAY_GO added some links that should be able to help you calculate what's needed.

Doug, this combo is exactly what i have w/37" MTR's and like I said above, it ain't workin. I am using the power 29969 with the CJ power booster, 1/2 ton GM calipers in front and Explorer brakes in the rear. Good luck with it.

Not sure if this will help or not but, I also tried the vette master cylinder. Rear brakes worked great fronts did not. I have the larger mid 80's jeep discs up front and el dorado discs in the rear. I tried several vette masters with no luck. I then found out that in 1980 GM engineers came up with a "low drag caliper" increasing fuel economy. What they did was change the bevel on the caliper piston seal, this little change would cause the piston to retract when the brakes are not applied. They also found out that a standard master cylinder would not work with them. So they developed a "quick take up master cylinder", which would force the caliper piston against the rotor, with the first step of the master cylinder, then it would function just like a regular master cylinder. Ford, Jeep and Nissan also switched to this low drag caliper shortly after GM.
So my choices were to change my calipers to something pre 1980 or change my master cylinder to something post 1980. I opted to change the master cylinder. I used one from a mid 80's s-15 truck, my brakes now work great!
Here is a link that talks about the low drag calipers,click here (http://www.babcox.com/editorial/bf/bf60133.htm)

Your other option was to get a disc brake residual vavle and put that inline. This would have keep slight pressure on the brakes and keep the piston from backing all the way out.

by the way, I run 76 GM 3/4 ton front calipers and medium size car calipers for the rear. no residual valves and my brakes are perfect.

Before I canned the vette master, I did install residual valves front and rear along with an adjustible proportioning valve, they didn't help. Changing the master was the cheapest route. I'm currently building a set of dana 60's and I plan on using pre 80 brakes and the vette master. I think that WheelingPiazza is correct that the vette master is an awsome master to use, I just wanted to share what I learned.

Originally posted by shelljeep
Doug, this combo is exactly what i have w/37" MTR's and like I said above, it ain't workin. I am using the power 29969 with the CJ power booster, 1/2 ton GM calipers in front and Explorer brakes in the rear. Good luck with it.

Try ditching the porp valve to get more psi to the front brakes. Just a cheaper suggestion than getting more m/cs or calipers.

Originally posted by JeepinDoug


Try ditching the porp valve to get more psi to the front brakes. Just a cheaper suggestion than getting more m/cs or calipers.

Can't hurt...

Here's my setup:

79 Pontiac Firebird MC
Mid-80's GM Dual diaphram booster
stock 82 CJ Proportioning Valve (unmolested)
Stock 82 front calipers
Lincoln Mark series (I think II) rear calipers.
stock lines

I have great brakes with 37's. My pedal is right at the top. I use less than a quarter of stroke to stop in a hurry. I achieved the pedal by creating an adjustable brake rod (elsewhere in this thread). Other than that its pretty straight forward.

I researched for days about the COMBO valve or porportioning valve used in a 82 CJ. I still don't know which on it actually is but I ran it and tested them to see how much, if any, pressure was put on the rear caliper. After about a year, the rear pars have not worn as much as the front so I would not think they are dragging from residual pressure.

The best upgrade from a drivability standpoint was adding the dual diaphram booster. That was very easy to do and made the pedal more responsive. I'm very happy with it.

Now that I have changed to a d-44 hysteer setup and the larger chevy calipers, I don't know how my brakes will be affected. If there is a significant change, I'll let you know.

Just my experience.

Scott

Noone has mentioned the pedal ratio factor or replacing/removing the factory prop valve.

What the MC came off of is irrelevant. A 1" bore MC is going to produce x #s of line pressure per # of input force regardless of anything else.

68 corvette, 76 pinto, 03 Kia.....shouldn't matter! The ole saying that if you go from disk/drum to disk/disk you need to get a disk/disk mc doesn't make any sense. All a mc is, is a pump and the bore of the pump cylinder is the deciding factor in how much pressure it is going to produce in relation to input force. The only really diffecence is the volume of the fluid holding area. No different than trying to decide what size ram to use for hydro steering.

I would bet that the problem that most of you guys are experiencing is because you are still running a disk/drum factory prop valve, or you have swapped a factory equiped power brake to non-power and didn't adjust the pedal ratio.

Personnaly I don't like the wilwood style prop valves. They don't actually "proportion" brakes, they just reduce the line pressure that makes it to the rear calipers. A factory prop valve trully balances the system and is much safer.

Sorry to bring this BTT, but I wanted to finish what I was discussing earlier for future searchers...

I installed a dual diaphragm vacuum booster last night, it made all the difference in the world once I fine tuned my set up a lttle bit more.
As soon as I installed it, I noticed a lot more response with much less pedal stroke. Unfortunately, it was still less stopping power than what I wanted. The majority of the force was on the rear, I still couldn't get the front to lock up.
So I swapped the lines again and got rid of the adapters I had mentioned earlier. This improved the brakes ALOT:D . Pedal stroke was a bit longer, but effortless! The rear will still lock up sooner, but the front is definitely getting more force this way. ( I thought this may have been a fluke, like due to bad bleeding before or something, so I switched lines again, reinstalled the adapters, bled it to death, tried it, and had to swap them back afterwards :emb2: )

So, here is the combo I found worked for me:
'68 Vette MC for power brakes
'85 Blazer dual vacuum booster
TriCounty adjustable brake rod(used to increase pedal ratio)
Remove residual plunger from combo valve
'97 Explorer discs in rear
'78 GM 1/2 ton(or 3/4) calipers in front
I may get an adjustable proportioning valve in the future to finetune the bias front to rear.

Hope this helps somebody.

Good to know and glad it works now, congrats.

Here's my setup:

79 Pontiac Firebird MC
Mid-80's GM Dual diaphram booster
stock 82 CJ Proportioning Valve (unmolested)
Stock 82 front calipers
Lincoln Mark series (I think II) rear calipers.
stock lines

I have great brakes with 37's. My pedal is right at the top. I use less than a quarter of stroke to stop in a hurry. I achieved the pedal by creating an adjustable brake rod (elsewhere in this thread). Other than that its pretty straight forward.

I researched for days about the COMBO valve or porportioning valve used in a 82 CJ. I still don't know which on it actually is but I ran it and tested them to see how much, if any, pressure was put on the rear caliper. After about a year, the rear pars have not worn as much as the front so I would not think they are dragging from residual pressure.

The best upgrade from a drivability standpoint was adding the dual diaphram booster. That was very easy to do and made the pedal more responsive. I'm very happy with it.

Now that I have changed to a d-44 hysteer setup and the larger chevy calipers, I don't know how my brakes will be affected. If there is a significant change, I'll let you know.

Just my experience.

Scott

Can you give me a better idea on what year and model GM booster you're using? Whats the diameter of it, and does it use the stock CJ bracket that comes off of the fire wall 4" or so.Thanks!

Beating an old thread but, I have a CJ with a 82 Corvette M/C for power brakes and a Caddy dual P/B and a MP disc/disc P/V. Have Chevy truck calipers on all four corners. Brakes work ok but seem to be lacking in the rear. Climbing uphill or on rocks the brakes lack holding power. Might a M/C from a Corvette for manual brakes be a better choice?

Chevy 1/2 ton calipers on both axles?

Sounds like you still have the stock proportion valve on. Replace it with an adjustable one.

http://www.summitracing.com/search/Department/Brake-Systems/Section/Proportion-Valves/?Ns=Rank%7cAsc

The 8 year old post with pics don't work anymore. Does this look like the correct part? Going on an 86 cj7 with D60 front and 14 bolt rear both with 3/4 ton Calipers.
http://www.autozone.com/autozone/catalog/parts/partsProduct.jsp?displayName=Master+Cylinder+(Brak e+System)&itemId=7-0&navValue=14400007&parentId=44-0&productId=718049&fromString=&itemIdentifier=718049_0_0_3482&filterByKeyWord=&categoryNValue=&isSearchByPartNumber=&categoryDisplayName=Brakes&store=5686&skuDescription=FencoReman/MasterCylinder(BrakeSystem)&fromWhere=&searchText=&_requestid=2463228

http://www.pirate4x4.com/forum/showthread.php?t=860622

This has been covered a lot.

The new build has d60/14bolt with 3/4 ton brakes. stock 90 yj booster, 78 vette m/c adjustable proportion valve, works great.