For months I have been slowly working on the brakes on my SVP. They drag/hang/catch whatever you would like to call it. They make a light roaring sound when driven. It was worse but slowly improved with everything I have done but no where near where it should be.

9 MPG and the car drives like it is struggling to pull and anchor. When raised off the ground the front wheels barely spin around once, the rears are not much better. It seems the brakes just will not release...

The fronts brakes were fairly new all around but do have a vibration. Likely due to bushings I will be replacing. Despite looking clean, I rebuilt both front calipers, new pins, boots, seals, etc. Pads and rotors are almost new.

The rears have rebuilt calipers, new pads and rotors. The parking shoes do not seem to be an issue.

Despite all the rebuilt parts and the new ones they continue to drag horribly.
It is not just one set that holds.

Since it seemed to effect all I have had the fluid gravity bled and also pressure bled twice to make sure there was no air in the system. No air in the ABS and none in the lines. I did not do this part but my indie swears there is no way there is air in there as they ran a lot through the system.

When the calipers are off the rotor they can each be pressed back in by hand with pressure. That led me to the master cylinder and booster.

Today I tore into the master cylinder figuring it was the culprit. With a bleed and test kit everything looked good. Very good actually. I played with the booster and would have adjusted it but seemed to be dialed in about right.

I am about out of answers here. The only thing I can think of at this point is a small vacuum loss or something that is not pulling the fluid back up. the MC seems to work perfectly.

Any ideas?????

 

Based on the above symptoms, my repair book says it is possibly one of the following:
1. Binding brake pedal. Free up and lubricate.
2. Soft or swollen rubber parts caused by incorrect brake fluid or contamination. Replace all rubber parts, flush brake system, refill with approved brake fluid.
3. Plugged master cylinder compensating port(s). Repair or replace the master cylinder.

Hope this helps.

 

Helps some. Haven't checked the brake pedal but think I would have noticed that......

Rubber parts. Only ones I can think of are the two grommets in MC for reservoir and gasket to booster. I'll check a parts diagram for others.

The MC and ports seemed fine today when flushed out. To be honest this is the first time I've taken one out and bench tested. I'll have to look into cleaning-testing the ports.
A reman MC is a little over $100. I'd hate to just start throwing parts at this.

Business is booming this year and I can hardly keep up. I no longer have the time nor the patience for this car. It is a real shame as this is a nice car and I have put in insane amount of time and labor in it (over $2k in just parts) in the 6 months I have owned it. That is about 3X the mileage I have put on it in the same time..........

 

Col , are the brakes binding when cold , or do they get worse the more you drive ?

 

Have you changed the brake hoses?


Had a Rover a few years ago and the rear brakes would not release properly, it was the rubber brake hose to the rear axle.

 

I have not. Looked at ordering last night and in my cart. It's just getting harder to throw more parts and money at this car as I'm just done with it.

Going to order everything possible and change out until things work.

They drag all the time. They brakes don't seem to get too hot and warp but it is very noticable

 

I think before I would spend another dime I would jack up all four wheels, release the parking brake and try to turn the rotors to see which wheel is causing the issue. Then have a partner hold the brake down and check the brake lines, looking for bulges.

All disk brakes will have a light drag: but yours seem to be much stronger.

OBTW: what year and model (SVP ?); and where is it? Very humid area could cause rusting on the rotors . . . location is important!

 

I've had the car up off all four wheels more times than I can count. All wheels drag, fronts worse that rear. I have not closely inspected hoses but for $10 a piece I'll just replace and mark off list. ----half the car is new and rebuilt..

Car is in Ohio, being a 2001, it is probable that these parts are worn

 

Just a thought but were the caliper pistons OK, you didn't mention them when alluding the the caliper rebuilds. If the car is braking OK you have good fluid pressure it would seem to me, something is preventing the pistons from retracting properly under normal braking pressures, As jhartz says, check the motion of the pistons while someone applies the brake pedal, although it seems odd that all 4 corners have a problem..... Fortunately the Teves calipers only have one piston each to worry about.
You mentioned a vibration, maybe worth cleaning the ABS sensors while you're in there tearing your hair out....

 

Assuming the front disks are not warped, pull the pads, review your installation process, sounds like the pads (and backing plates) are too thick or the pistons are not receding . . .

 

I have pulled the pads off all 4 multiple times. I've taken all calipers off, wire-brushed and cleaned, re-greased and put back together. ABS sensors cleaned, parking brake adjusted and everything else I can think of.

As I mentioned, I will be putting this up for sale soon. I am too busy with work.

So to speed process up I went ahead and ordered front calipers, brake lines, new master cylinder and lots of Dot 4 brake fluid.

Combined with everything else almost the entire brake system is new. Add in the bushings and 100s other items and it may have been quicker to build a new car from scratch.....

 

Col , you sound pretty frustrated and just about reached the end of your patience ,

If you are prepared to do a few simple checks , I will try to help you .

These are checks that you have not done yet

Sid .

 

Thanks. I am getting to the end of the road with this. Too much time and money for no driving. I expected some work but this has been murphys law. Who gets a batch of bad wheel bearings???

I'm open to suggestions

 

Are you with the car , if so are the wheels off the ground ?

 

not with car. over at other house. in air, wheels off, master cylinder removed

 

Did you note if the wheels/rotors turn with Master Cyl off the car

 

Do you mean rotors and not backing plate??

I to thought about this. Not by choice here.... I've installed new aftermarket rotors and pads (Primarily in the front I've encountered this) only to struggle getting the loaded caliper to slip over the rotor. We had to go with another set of brake pads is what I remember as it's been a few years ago.

Did you use proper caliper pin lubricant?

 

It has been a while since I have done the pads on my car: but some cars have pads, and a shim or backing plate between the piston and pad, I have seen pads that had the shim embedded in the new pad, not seeing a separate shim (or backing plate), you could make a mistake of installing the old shim causing excess thickness.

Other thoughts: wrong pads, try a different brand that is not so thick: easy caliper check: measure the ones on the car, find another brand, check, if thinner, buy. I am missing the point on replacing the master cylinder.

 

Oh geez, I was thinking rotor backing plate.
Yeah, I've come across that. Gotta love aftermarket crap! Some of it's good though, but not much of it.

 

I went over the car for a few minutes today. Had family around so I could only sneak out for a few minutes. I appreciate everyone's help with this. What an adventure!

Here is current status:
The MC is attached to booster and the brake lines but no fluid in it. Fluid in lines. Rear calipers are off as well as pads and carriers. The rear pistons were out only a bit and I was able to push them back just a bit.

With front wheels off still I could not turn the rotor with the calipers on.
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As I mentioned, I have already remaned the front calipers. Pulled pistons, cleaned and polished, replaced the o-rings and seals. Slide pins were removed and polished to a shine. I would have replaced the rubber sleeves but they were in great shape. cleaned calipers, carriers, and pads with wire brush, I lubed everything and assembled.
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I pulled the front pads and calipers off today and could not get them to budge. There are no extra shims/backings/other stuff on the pads. I did look over the brake lines and they look a bit old but nothing bulging.

I will look again to see if the thickness of the pads+rotors has the calipers maxxed out. I doubt it but will double check again. I've got a few days until the rest of the brake system parts show up.

Outside of a stack up issue with pads and rotors against the caliper I'm out of ideas. The only thing left is the ABS unit. I took a picture of it just to feel like I did something today.......