I have just finished swapping in dana30 wide track in the front and a 9" ford out of a 66 bronco in the rear of a 1994 YJ the front has the 78 6 bolt calipers with the thick rotors ( best brakes put on a CJ) and 1979 rotors on (a little thinner but still vented) the rear. the rear has s10 calipers. I also replaced the master cylinder with one from a E350 ford van....... also removed the proportioning valve
Now the trouble..... I have no brakes after running 3 quarts of fluid through it and and removing the proportioning valve... it akes 5 pumps to get any pedal at all......

any ideas....
thanks
archie =) =) =)
P.S. I did run it around the block with no brakes :)

I have just finished swapping in dana30 wide track in the front and a 9" ford out of a 66 bronco in the rear of a 1994 YJ the front has the 78 6 bolt calipers with the thick rotors ( best brakes put on a CJ) and 1979 rotors on (a little thinner but still vented) the rear. the rear has s10 calipers. I also replaced the master cylinder with one from a E350 ford van....... also removed the proportioning valve
Now the trouble..... I have no brakes after running 3 quarts of fluid through it and and removing the proportioning valve... it akes 5 pumps to get any pedal at all......

I hate no pedal brake tech posts, it's always the same ole shit.

Did you use a good brand of master?
Did you make certain the bleed screws are absolutely above the banjo bolts where the flex lines attach so you can actually get the air out? (don't say yes, go look)
Did you set the pushrod length on the master to the booster?
Describe your bleeding method and please tell me you didn't do a gravity or the ole "pump it three times and hold it" bleed?
Did you bench bleed the master?
If so, what method did you use?
S-10 front or rears?
What diameter are your front pistons?
What diameter are your rear pistons?
What is the bore of the master you used?
Did you let the master run dry during the bleeding?
What happens to the pedal, engine off vs running?

any ideas....
thanks
archie =) =) =)

I got a bunch of ideas, none of which are applicable until we get a bit more info.
P.S. I did run it around the block with no brakes :)

I knew you were a bit off when you ran 3 quarts of fluid through the calipers and you driving around the block with no brakes confirms it. Neither of which I'd be proud enough to tell anyone about.

If you don't get a pedal after fluid shows at the bleed screws and max 5-8 strokes per wheel, then you need to stop and find out what's wrong because all you doing is getting some exercise and wasting brake fluid.

Finally, I hope you didn't toss that prop valve too far.

Mr blaine.....
I had a nice reply all typed up and I was not loged in and it went out into the void somewhere.....

I am not sure exactly what you are referring to as

"Describe your bleeding method and please tell me you didn't do a gravity or the ole "pump it three times and hold it" bleed? "

I am not sure there is any other way to do it besides using a bottle with a vacuum hose and I tried that too.

and I am not some newbe..... My build thread is here.

http://jeep534.smugmug.com/gallery/732903_zkPAJ#484110243_qFUp2

all of the calipers and master cylinder are rebuilt units from advance. after going through all of it I blocked off the master cyl ports and it pumped up solid. (so the master is not bypassing)

The pedal is the same with the engine off or on. the pushrod is correct and I feel it it a volume problem. after sleeping on it I am betting that the master cylinder is not putting enough fluid to the rear brakes.

archie =) =) =)

I am pretty sure the master cylinder is putting enough fluid to the rears.
I use the e350 on my 3/4 ton chevy calipers in the rear and 1 ton chevy calipers on the front and it works great. Sounds like a air problem in the lines.

Did you bench bleed the master cylinder??

I am pretty sure the master cylinder is putting enough fluid to the rears.
I use the e350 on my 3/4 ton chevy calipers in the rear and 1 ton chevy calipers on the front and it works great. Sounds like a air problem in the lines.

Did you bench bleed the master cylinder??
I bench bled it and after screwing with it for a long time I bled it again on the jeep??????
archie =)=) =)

I bench bled it and after screwing with it for a long time I bled it again on the jeep??????
archie =)=) =)

We can dance around this until the cows come home wearing hats with frilly flowers and until you answer the questions as they are asked, we may as well eat the hats.

HOW DID YOU BENCH BLEED IT AND WHAT WAS THE RESULT?

Here's why. It's very common for the rebuilders nowadays to use crap springs and crap parts in their masters. I've seen whole pallets of that junk up at Van's shop and he's had to take each one apart and inspect them after a few customers complained. They are not the "el cheapo" versions you get at the crap parts stores either.

Here's the number 1 rule of bench bleeding masters- If you throw in it the vise 3/4's of the way full of fluid, plug the ports, and it does NOT come up within about 10-15 strokes, take it back to where you bought it and get another one. {by come up, I mean you cannot depress the pushrod more than 1/16 to 1/8"} Good masters are very easy to bench bleed, give you no troubles and you don't have to screw with them. Since this is the heart and soul of your braking system, why would you?

Here's the number 2 rule of bench bleeding masters. It's called bench bleeding for a reason. Unless you have it nearly level in the vehicle (almost impossible to do without a lot of shenanigans) it won't come up, so take it out and put it back in the vise.

Mr blaine.....
I had a nice reply all typed up and I was not loged in and it went out into the void somewhere.....

I am not sure exactly what you are referring to as

"Describe your bleeding method and please tell me you didn't do a gravity or the ole "pump it three times and hold it" bleed? "

Gravity bleeds do not get all the air out. The only thing a gravity bleed is good for is getting fluid to the bleeders and then it's usefullness is over.

If you pump the pedal three times, hold it and then crack open the bleeder, all you are doing is aerating the brake fluid with thousands of tiny bubbles which you then disperse throughout the brake system where they later coalesce into larger bubbles which give you a spongy pedal.

I am not sure there is any other way to do it besides using a bottle with a vacuum hose and I tried that too.

Do this- Helper in driver's seat, you at the bleeder

You- open bleeder with hose in bottle (only to prevent spraying fluid everywhere and contain the mess) with as wide a swing as your wrench allows and then say Down

Helper upon hearing the Down command, depresses brake pedal fully and enthusiastically and says Down when when it's down.

You-upon hearing him say down, close the bleed screw and when it's closed, give the Up command.

Helper upon hearing the Up command, lets the pedal up on a 2 or 3 count and says Up when it's at the top.

That method has never failed, has no issues or quirks and causes no other problems. Use it as I described.

and I am not some newbe..... My build thread is here.

http://jeep534.smugmug.com/gallery/732903_zkPAJ#484110243_qFUp2

all of the calipers and master cylinder are rebuilt units from advance. after going through all of it I blocked off the master cyl ports and it pumped up solid. (so the master is not bypassing)

Bypassing is not the only issue a crap master can have.

The pedal is the same with the engine off or on.

That's bad.

the pushrod is correct How do you know the pushrod is correct?


and I feel it it a volume problem. after sleeping on it I am betting that the master cylinder is not putting enough fluid to the rear brakes.

If that's truly the case, you said that wrong. What you should have said is I paid no attention to sound brake bias principles and selected calipers for the rear brakes that are way too fucking big.

archie =) =) =)

I'll go out on a limb and second MrBlaine's approach.:grinpimp:

I verified the pushrod length today.... Yesterday I plugged off the master cyl and it was a solid pedal.
I personally have never tried to bleed that way. oh well..... maybe tomorrow.

"If that's truly the case, you said that wrong. What you should have said is I paid no attention to sound brake bias principles and selected calipers for the rear brakes that are way too fucking big."

I used the calipers that matched the bracket's I could locate. and I believe when it is all said and done it will work out alright.

I am probably just going to put it on ignore till next weekend and take another run at it.
archie =) =) =)

I verified the pushrod length today.... Yesterday I plugged off the master cyl and it was a solid pedal.
I personally have never tried to bleed that way. oh well..... maybe tomorrow.

I give up.

"If that's truly the case, you said that wrong. What you should have said is I paid no attention to sound brake bias principles and selected calipers for the rear brakes that are way too fucking big."

I used the calipers that matched the bracket's I could locate.

That's equivalent to saying you found size 54 thong panties on sale at Walmart and and married the first girl they fit.


and I believe when it is all said and done it will work out alright.

Cool beans, then my work here is done.

I am probably just going to put it on ignore till next weekend and take another run at it.
archie =) =) =)

I wish you the best of luck.

I finally have a brake pedal....... after getting another master cylynder verifying the push rod length, bench bleeding it with plugs and bleeding it all out on the jeep i still had the same result. no pedal. there was still air in the system. the bleeders on the front were pointing up however, the passage is apparently not at the top. I pulled the front wheels of and the caliper off and set it on top of the rotor. put a stick on the brake pedal and when I opened the bleeder air came out. I did both of the front calipers. and I now have brakes. there is still some air in the front but it will stop without pumping them. after i figure out which braided lines to use on the front i am going to swap those out and do a final bleed, put a pro portioning valve and park lock in the rear line and call it good.

I need to address a few other items before i can put it back on the road. I need to fabricate a track bar mount. I found the stock for that at the scrap yard this week. when i took the jeep back on the hill yesterday the shifter was rubbing the dash in first gear so i need to heat it and bend it just a bit. (i lowered the motor just a tad which caused it to hit) I also need new shocks and to get the front end aligned. but all in all it is running great and the axle gearing is spot on.

Happy Hunting
archie =) =) =)

I have S-10 rear calipers on my Jeep and they bring the suck! I tried all the above and the only solution that worked for me was to use a manual mc for the S-10. I plumbed the mc so the traditional bowl that powered the front calipers now supplied fluid to the rear S-10 calipers. In my research I found out "thanks WheelingPizza" that my S-10 calipers were "quick takeup" design and needed a quick take up MC. Since switching to this MC my problems are now gone.

1/2 ton Chevy calipers in front
S-10 front calipers in rear
S-10 manual MC

..........the bleeders on the front were pointing up however, the passage is apparently not at the top.......

Not disputting what you said, but how could that be? :confused:

NIB

Not disputting what you said, but how could that be? :confused:

NIB
I went back to the parts store and did some more checking and they are the correct calipers but I believe I have them on the wrong sides. I will leave it as is until I get the correct brake hoses. the wrangler hoses I modified will not fit When I swap (flip) the calipers side to side. I will need to replace them with a stock hoses from the 78 jeep or maybe braided lines which are a little bit more expensive.

Thanks for everyone's help
archie =) =) =)

Good to hear you are making progress. I bought a rear axle off of a '97 ZJ last week for $75. I plan on swaping the disc brakes over to my TJ later this year. I'm sure I will run into all kinds of problems when I do; but that is part of the fun..........I guess. :)

NIB

Good to hear you are making progress. I bought a rear axle off of a '97 ZJ last week for $75. I plan on swaping the disc brakes over to my TJ later this year. I'm sure I will run into all kinds of problems when I do; but that is part of the fun..........I guess. :)

NIB
There were many days and nights where I wondered why I tore apart a perfectly good running jeep. :)

Yes, it just don't make no good sense. I figure I will quit "improving" my TJ when I have as much money in it as my wife does her 2003 Vette. I'm afraid I don't have far to go. :homer:

NIB