Soft Brakes/suggestions

[Challenger]

Hello,

Just did the 96 brake upgrade on my 95MTX and the brakes just dont feel right! I replaced the left rear caliper a year ago and since the brakes have never been the same, bleed the rear brakes at least 8 times no signs of air(used the hose in the bottle method) and just can seem to get a hard peddle.

Brakes seem to stop ok but peddle is low and if I pump it up it will pump up after 3 or 4 pumps then slowly go back down, doesnt go to the floor and dont think its the master cylinder but could be wrong, waiting on my speedbleeders to arrive and then I'm going to flush the brake system, I've never done it before running on orignal fluid with 80k on it.

Any sugestions??? I could use some impute on this one. THANKS

Paul Michael....95 MTX

 

[Mr Anonymous]

Just out of curiousity, did you bleed in the correct order? (RR, LF, LR, RF)

If so, and you're sure there are no leaks, you might also want to bleed the ABS pump.

If you're sure there's no air in the system, and all your pads, rotors, and brake lines are in good shape, then you could be looking at a master cylinder problem.

 

[Challenger]

SHOooo, I have not bleed the whole system just the rear. I will be doing the flush as soon as my speedbleeders arive. I only have done the rears at this point!

From what I've read isnt the correct way to bleeed the brakes RR,LR,RF,LF ? Thanks thats what I've read and thats the way I was going to do it.Is this correct??

Has anyone ever used the tool reccomended in the service manuel to do the flush?? The tool I'm talk abou is the one that plug into the main wiring harness and opens all the valves in the abs??? I may have acess to one of the tools?

Thanks again...........Paul

 

[Mr Anonymous]

Challenger:
SHOooo, I have not bleed the whole system just the rear. I will be doing the flush as soon as my speedbleeders arive. I only have done the rears at this point!

From what I've read isnt the correct way to bleeed the brakes RR,LR,RF,LF ? Thanks thats what I've read and thats the way I was going to do it.Is this correct??

Has anyone ever used the tool reccomended in the service manuel to do the flush?? The tool I'm talk abou is the one that plug into the main wiring harness and opens all the valves in the abs??? I may have acess to one of the tools?

Thanks again...........Paul

The bleeding order is RR, LF, LR, RF per the shop manual, and is the best way to completely get air out of the system. (Page 06-06-15 in the '95 shop manual if you don't believe me.)

I've never used one of the pressure bleeders, but I guess it would be a good way to ensure the entire system including ABS was purged.

 

[rangerj]

The only way to properly bleed the ABS is to access the ABS via the computer, so that the various cylinders in the ABS pump are put in the position for bleeding. This can only be done by a dealer service department, or a shop that has the proper computer access equiptment.

Few small shops have this equiptment because it is expensive, and not used often enough to justify the cost. A dealer will charge about one hour labor to do this. This will be about $70 to $100 in labor to bleed the brake system.

I have had no difficulty taking a vehicle to a dealer for a full brake system bleed, including the ABS, where I supply the fluid of my choice.

Read the SHO Times discussion about brake fluids. You want to use a brake fluid that will withstand heat, and has a low moisture absorption quality, such as Castrol LMA (low moisture activity). The fluid you chose should meet DOT 4 standards, at a minimum. The "blue light special" just will not cut it.

At 4% moisture your brake fluid is just about worthless, and brake fluid naturally absorbs moisture! Completely flushing the system with fresh fluid every few years is OK, but every year is best.

As for your low, and/or dropping brake peddel, if there are no leaks and no air in the system, then it is most likely the master cylinder. rangerj

 

[Challenger]

Thanks ,

For the suggestions, I installed the speedbleaders today and flushed the system, still have a soft mushey peddel, doesnt look like air in the lines at this point, after 1-1/2 quarts of fresh fluid and no better.

I did use the reccommend bleeding order(Thanks SHOooo) I'm thinking it may be time to go to the master cylinder, never did a master cylinder on a SHO but thats the next step at this point.

Thanks again .....Paul

<small>[ October 07, 2002, 10:28 PM: Message edited by: Challenger ]</small>

 

[ManySHOs]

I think that you guys have it backwards. You want to bleed the longest line to the shortest. That would be
1. Right rear
2. Left rear
3. Right front
4. Left front.

Ian
93 mtx blue

 

[Slo-Sho]

The guy above just gave you info directly out of the shop manual. Why do you think he is lying?

 

[RStalveyARFF]

you said your car has never been the same after you replaced that caliper. That's what we need to look at. Did you replace the copper gaskets with the caliper? Also how tight did you torque it? Replacing a caliper won't blow out your master cylinder, let's start cheap.

 

[Challenger]

Hello,

Yes I did replace the copper gasket when I replaced the caliper. I also bled the car on the ground and went through about a 1/2 quart of fluid, still felt soft Mushey like air in the lines.

Drove it a couple weeks and removed the caliper and got another rebuilt and went through the same thing and the brakes felt about the same. Drove it like that for about a year and then went to the 96 upgrade and flushed all the fluid, went with speedbleders and 2 quarts of fluid and it does stop better but it doent have the high hard peddle my wifes 98 SHO has.

I do have access to the computer controller that opens all the abs valves to bleed the abs and I was thinking of going that route next, still not convinced its the master cylinder. Thanks .....Paul

 

[rangerj]

Re. bleeding brakes,

Since the advent of duel safety master cylinders, back in the 60s, the bleeding sequence has changed. The early system simply divided the brakes into front and rear.

More correctly, the bleeding sequence changed when the brakes were divided into one front and one opposit rear with each end (front and rear) of the divided master cylinder.

The old standby bleeding method, that is bleeding the fartherest brake cylinder from the master cylinder first, and then working up to the closest, is obsolete.

The safest bleeding proceedure for these "new" cars is to follow the OEM prescribed sequence.

This post is for some of the younger folks who do not know that cars did not always have a computer and CD player in them. And PLEASE, I say this in jest, so don't anybody get POd. rangerj