Friends,

I got my '87 S4 on the road after it had sat for 5 years. I replaced the usual TB, FP and put a new radiator in it.

My mechanic ran it and drove it only in his parking lot. It runs/idles/revs just fine. When it was ready, I eagerly ran over and picked it up for my first ride in the car.

So in short up to this point it has only been taken off of the trailer pushed into the shop, driven around the parking lot-all of this activity using the brakes and them functioning sufficiently.

I left the mechanic, fueled up and took local streets for the 10 mile ride to south Austin where I live. I didn't want to put in on the expressways; it was rush hour anyway and should I have a problem I didn't want to be on the side of a highway...

It was a slug to drive-throttle/KD cabling needs to be adjusted but I was happy to be in my shark. I took it easy watching the temperature-everything fine.

So I'm in stop and go traffic for 6 miles or so, with speeds reaching 40 at times, roughly 30 minutes into the ride at about 35-40mph the brake pedal goes all the way to the floor. Frightening, but I pumped the brakes and the pedal returned quickly- a little spongy for a sec but soon the pedal was back to a firm feel. For the rest of the ride I had my hand on the emergency brake which functions just fine I learned. I didn't have a close call or anything I got it under control quickly. For the rest of the trip home the brakes worked as normal.

I got home, parked the car and am not taking it back on the road until I do some work on it (flex plate assess, fuel lines).

I have done a couple turns in the neighborhood. Last night I took it for a spin and got up to 25-35 and applied the brakes hard-did this a number of times. The car stopped very well and the brakes never got spongy they were firm-worked very well.

So what should I do?:

Get a new master? Bleed the brakes fully? Is there a rebuild kit for an '87 master?


I do not want this to pop up unexpectantly again - I run the risk of losing control really hurting somebody /causing a wreck. Please advise.

 

At the very least change the brake fluid, it needs to be done regardless.

 

I agree the first thing is bleed/change the fluid. Next would be you need to inspect the brake lines with a fine tooth comb to make sure everything is in good working order. Have the brakes been touched at all recently?

Could have been air in the lines but how that got there is the question.

 

I would do the Master and then a full can fluid flush.

Your story is a good wake up call for all those 20 something year old car owners out there for the need to have a properly adjusted and working E Brake!

Thanks for sharing,

Dave

 

just brakes 101. i would not rebuild a part that old [master cylinder] .check ALL brake lines/hoses for bad rusting,cracks etc

 

Be careful when you look at the calipers, the dust boots and seals are NLA for '87.

 

Same thing hapend to me Saturday night. After been in a stop and go traffic for about an hour and a half everything seem fine, car was running good temp about half way up. Got few thumps up (don't know if was for the car or the wife) And then as soon as the road cleared and I took off thru the gears hit about 65 the car front of me starter to slow down, so I hit my brakes and the pedal went right to the floor.

Pump the pedal few times nothing no pressure at all. Move over to the right lane downshift it quick and got the car stopped. Got off the highway parked car 20 minutes later brakes were fine. Turns out right front caliper was sticking boiled the fluid. Got it back from rebuilder before put it on car and still inside pistons are not moving at all.

 

New master, clean the reservoir, and new brake lines if they are old.

 

For the "slug to drive" issue, and considering it sat a while, you may want to also ensure the exhaust (resonators,cats, etc) and the air intake system is clear and not partially clogged. Rodents like to use exhausts and other tunnel areas of the car for nests and food storage.

Also check for proper ATF level.

 

Suggest you flush all brake fluid and refresh with a good quality DOT4 or 5.1. Chck for any leaks. Check the brake booster operation and any vacuum leaks, etc.

 

Not correct and readily available - 928 351 919 00

 

You sure Roger? There were NLA a few years back, you needed to spend $50 per piston to swap to newer style to get the job done. If they've gone off and remade them I'll have to grab a set for my car!