supra master cyl ???

[Rockmonky]

do they have a residualy valve for the front?
driveing it for the first time at speed and the cruza seamed to be geting slower and slower then i smelled brakes so i pulled over and the fronts were hot as hell and i had like a 1/2in of pedel movement
i also took out the factory perportioning valve when i did the swap
i was thinking that i might have the push rod ajusted out to much causeing it to holding preasure on the brakes


any idea's
thanks Tim
and i know i cant type or spell

[ranger]

I attempted this swap also to no avail. I had to reuse a stock tlc master cyl. Why the front brakes kept locking up, I couldn't figure it out. I still hacve the supra m/c but it's one of those thing I back shelfed. I think arndog had the same problem awhile back, but I don't remember him posting a solution. <IMG SRC="smilies/skull.gif" border="0">

[Rockmonky]

well thanks for the discuriging advise
i have never had so many dam probs with masters this is the 4th one in 2 years

[Jettech]

I have no problems at all with mine,It works perfect with my 4 disc brake setup.
I didn't remove or install any valves,just ran it straight from the junkyard.

Rob

[flexing40]

i was thinking that i might have the push rod ajusted out to much causeing it to holding preasure on the brakes

The pushrod clearance is critical. If you were braking of and on as you were driving along and then the front brakes became tight I would highly suspect the pushrod clearance. Also another indication of lack of proper clearance is; if after sitting for a time the brakes are ok. Hope you find the solution.
Mike

[SpaceGhost]

Caution: this posts contains generalizations and is not an attempt to profess expertise or superior knowledge.

Regarding the brakes tightening up after use:
If you don't have the correct gap on these rods the master culinder will not return to the point that the fluid (under pressure) can return to the reservoir.

There are 2 adjustments for the 2 pushrods that will effect this. 1st make sure the rod that connects to the pedal is adjusted so there is play before the rod actuates the booster.

The second is between the booster and master cylinder where you will find the booster rod is adjustable. You have to seperate the master from the booster and tighten the rod end so there is an air gap. You should be able to do this without removing the lines. This is difficult to determine and might take a few adjusts/checks to get it right. Too loose is better than too tight.

You can test this without driving the Cruiser by just running the engine and cycling the brake pedal for a few minutes, if it still gets tight, keep adjusting. You can also lift one of the front wheels and see if it dragging.

Disk brake circuits do not require residual valves unless the master cylinder is positioned below the calipers. There is no return force on the brake pads. Street rods and race cars may have this configuration and the fluid will gravity flow from the caliper/lines back to the master cylinder reservoirs.

Drum brakes (wheel cylinders and springs) do require the valves to compensate for the spring pressure that returns the wheel cylinder to rest and pulls the brake shoes away from the drums surface.

Because I have read posts where these two terms/items were discussed as though they were the same:

Residual valves are completely different than proportioning valves. A proportioning valve, whether adjustable or fixed (as found on stock front disk/rear drum vehicles) reduces line pressure to balance the braking force, usually front to rear. This is needed to compensate for different forces, front to rear weights, braking systems differences (disk/drum) with the common intent to place most of the braking on the front axle. In a Cruiser with 4 wheel disks (and the same caliper piston surface area which is not the case with the GM calipers) the rears would lock up first because most of the weight is on the front axle. This would be most noticable on loose traction surfaces (rain/ mud/gravel), going down steep inclines, or during hard/panic stops. During normal on road driving it may not be detectable.

Master cylinder selection is another confusing area. The FAQ section at Wilwood gives some info for determing the correct cylinder bore with relation to the pedal ratio and caliper piston surface area. Typically on Cruisers anything with a 1" (25.4mm) or larger bore will require more pedal effort to stop and is less favorable than a 7/8" bore.

This ended being way more info than required to help Rockmonky dial his brakes in. Add or correct my info as needed <IMG SRC="smilies/confused.gif" border="0">

Mike

[Rockmonky]

Thanks Alot for the help guys!!!!
i think my rod is ajusted out to much
cuz i checked it today and the pedle is fine
so i will play with ajusting it tomoaro
the weard thing is with out runing any residual valve in the back it still had a great pedel with drums <IMG SRC="smilies/confused.gif" border="0">
i was figureing it would need one or it would have a low pedle
i do need to get the ajustable perportaning valve in it though the back brakes lock up way to soon big tires locking up is such a cool sound <IMG SRC="smilies/biggrin.gif" border="0">

Agean thanks For the help

[The Jerk]

Originally posted by Jettech:
<STRONG>I have no problems at all with mine,It works perfect with my 4 disc brake setup.
I didn't remove or install any valves,just ran it straight from the junkyard.

Rob</STRONG>

same here

[Rockmonky]

I ajusted it in a little today and it seamed to work
have to drive it a little more to make sure
but it seamed to solve the problem
thanks all

[ranger]

Cool! <IMG SRC="smilies/biggrin.gif" border="0">