Well, this is a surprise.


The calipers are actually fine. It's the master cylinder that has failed. It actually doesn't push any fluid. It's so bad that I can't even try to bleed the brakes, nothing comes out the bleeders.

I usually tell all the parts dealers that I have a 98 to avoid confusion. They still told me that they didn't have it. But I'll go on their website and buy that part number.

I bought rebuilt calipers from Summit. They are A1-Cardone. Guess it doesn't matter if they are good or bad, I'm returning them anyway because I don't need them.

I ordered a new master from Lucky8 ans it should be here Friday. I couldn't find a wheel bearing kit on their website so I ordered it from their eBay store. For anyone that's gonna buy from them on eBay, understand that the handling time is 4 DAYS for some reason. Kinda ridiculous but what are you gonna do.

 

interesting that it was the MC - thanks for posting back

 

More surprises:

I have replaced the master cylinder with a NEW one from Lucky8, reservoir, and cap. Flushed the fluid and bled the brakes (twice) with new DOT 4 fluid. When the car is cold, usually on the first drive of the day, the brakes are perfect. So replacing the master cylinder made an improvement.

On the second drive, the pedal goes soft. There's no bulging in the rubber lines, and I am certain all the air is out of the system.

Any ideas? I'm thinking maybe the brake booster? Any input is much appreciated. Thanks.

Really tempted to try those rebuilt calipers after all

 

keep watching the fluid level to see if you got a leak....
did you bleed in the proper order.....
the passenger side front seems to want the most attention when I bleed mine.

I would replace the rubber hoses with SS braided ones due to age - regardless.

I read somewhere about bleeding the system at the calipers then pumping the brakes 5 times slow and cranking loose the 13mm (largest one) brake line at the ABS pump to get the air out of the top of the system - I dont have a link though sorry. (and I have never done it either)

have not heard of boosters going bad very often in my exp.

 

Have not noticed a leak yet but I am watching out for it. I did bleed in the order according to the shop manual.

Probably will replace the hoses at soon. But right now they seem like they should be functional; no dry rotting or bulges.

I will try bleeding the ABS modulator. Hopefully that works.

 

I just bled that one 13mm line and it didn't seem to help much. Really strange how the brakes are fine on the first drive after a cold start. Once I turn it off then on again, the pedal goes to the floor. The car still stops though. Any possibility that the new master is bad?

The A1 Cardone calipers are coming later today. If they look good to me, I'll throw them on and see what happens. Worst case scenario I'll just send them back.

I really hope that works. I don't like throwing parts at the problem. But this isn't my daily driver, so there's little urgency to get it fixed. But man do I miss driving it.

 

I feel your pain man - went thru a high idle issue for several weeks before getting it sorted.
was it a super cheapo MC?
do the brakes get worse as the vehicle warms?
did brake fluid get on the rotors or pads?

alot of places wont let you return once installed.

I cant stress enough the pain and cost I went thru with a super cheap caliper leaking and ruining brand new pads and rotor - not to sound like a broken record but Napa are the best remans I have found. not trying to tell you what to do by any means just was really frustrated after alot of work and 1.5 days of good brakes too being back at the drawing board.

 

Brakes do get worse as the car warms up. MC seems good quality. It's from AllMakes through Lucky8. Put one on my old D2 from AllMakes a few years ago and never had any issues.

Rotors and pads were never in contact with brake fluid. And I made sure to use a lot of brake cleaner.

 

man what a bitch
the reason I asked about heat is b/c my honda accord MC (for the clutch) I replaced with a cheapo - and everytime it got hot I had problems - replaced with OEM and works perfectly....no matter the temp

from what I understand - dot 4 is just able to withstand higher temps than dot3

I would keep an eye on fluid for now.

 

I know, I usually enjoy fixing and maintaining my trucks. Now it's getting a bit frustrating...

But I also went through the high idle issue and these brakes have not gotten to that level of frustration yet

So I just replaced the calipers with the new rebuilt ones. The rebuilt calipers look really good: looks like new seals, new pistons, new bolts, new bleeder valve, and even new slide pins and springs. Bled the air out with new DOT 4. And again, some improvement to the problem, but still not solved.

The issue has evolved to this: brakes are perfect cold; when warm, pedal sinks to floor when normally applying brakes, still stops the truck, but if I slam the brakes, pedal feels normal and brakes feel powerful.

Really stumped on this.

Edit: Could it be the brake proportioning valve?