Grabbing brakes then no brakes

[Niles]

On the way home from work today, the car was driving normally until I reached one of the roundabouts. As I pushed in the clutch to downshift and blend with traffic the car did not coast, but slowed down dramatically like the brakes were dragging. I had to downshift more to overcome the braking in order to get moving again. The only thing I could think of to cause this was the brake fluid was maybe getting very hot and expanding causing the brakes to start squeezing the rotors. But I could not figure out why the brake fluid would be hot since my drive did not involve any braking prior to the roundabout.

I then checked the engine temperature and it was above the top white line, but not in the red. I turned off the A/C and lowered the windows. It was hot today - over 100. I parked the car. Got out and checked the wheels and under the engine. A little bit of fine smoke was coming from the front wheels. Under the hood, the top of the brake fluid resevoir was wet. After letting it cool a bit, I started to continue home, initially the brakes were grabbing, but soon the car coasted like normal when I pushed in the clutch. Braking appeared to be normal until I pulled into my complex. My pedal went to the floor without slowing the car. I pumped the pedal and some braking returned. Continued forward again, but no brakes even with pumping except when pedal was all of the way to the floor.

Later this evening I went out to the car and the brakes were normal again. Has this happened to anyone else? Does anyone know what happened? I'm planning on flushing the brake fluid and checking my cooland levels, but I'm concerned about whether or not my car is safe to drive. Thanks for your input.

[Mrmerlin]

this sounds like a master cylinder problem, when you refit the new one pay attention to the pushrod thats coming out of the booster make sure it is not pushing the new MC when its bolted down. also check the adjustment of the pushrod in the car before fitting the new MC and after

BTW when was the last time you worked on the hydraulic system?? What fluid did you use?? I suggest that you use ATE super Blue racing fluid .
Everytime the fluids are mixed it creates the possibilty of a non compatible fluid and this will usually swell the MC seals and cause it to drag brakes

[Niles]

The car has 66,000 km on it - less than 50,000 miles. It doesn't seem like it would need a master cylinder, but it is certainly something I will be looking at. Since there are no leaks, it does appear to be a M/C problem. When I replaced the clutch master cylinder and slave cylinder, I used Castrol Dot 4 which says it compatible with Dot 3. I have no idea what the Japanese were using in it prior to my purchasing it. I don't know if the blue racing fluid is available here. I will look. Thanks Stan, I kniew you would come through with an answer.

[MPDano]

Originally Posted by Niles

The car has 66,000 km on it - less than 50,000 miles. It doesn't seem like it would need a master cylinder, but it is certainly something I will be looking at. Since there are no leaks, it does appear to be a M/C problem. When I replaced the clutch master cylinder and slave cylinder, I used Castrol Dot 4 which says it compatible with Dot 3. I have no idea what the Japanese were using in it prior to my purchasing it. I don't know if the blue racing fluid is available here. I will look. Thanks Stan, I kniew you would come through with an answer.

Well, you also have to consider that your car is 23 years old. Seals can fail, rust and corrosion can accumulate, etc. etc. I think Stan is onto something. Might be cheap insurance rather than your brakes locking up on on the highway with some Bonehead Texting as he tailgates you, then smashes into your car at 75 mph. Well, could happen.

[Niles]

You're right Leo, I will start looking. This is my only car right now. My jeep has a broken transmission. I'll probably have to order the master cylinder from the states. Thanks.

[MPDano]

Originally Posted by Niles

You're right Leo, I will start looking. This is my only car right now. My jeep has a broken transmission. I'll probably have to order the master cylinder from the states. Thanks.

Bummer on it being your sole mode of transportation. Is it that hard to get parts in Australia. Your Country if friggin huge! Where do you buy your parts from?

[Mrmerlin]

Roger has the fluid and the master

[Niles]

Stan, you must have read my mind. I was just on the phone with Roger and he has given me a quote.

Leo, Australia is huge, but the population is less than 10% of that of the U.S. There are Porsche places in Sydney, but the selection is not as good and they are very expensive. There are two auto part places in town that have the common parts and basic maintenance items for other cars. Even the Jeep has been somewhat difficult to find parts for. I'm actually an American living and working here. Life is good.

[Niles]

This is a follow up to my brake problem. It is now fixed. I replaced the master cylinder with one I bought from Roger. After I removed the old master cylinder, I was trying to drain the fluid out of it. I covered the rear port with my finger and tried to push on the plunger. It would not budge. It appears there was some kind of blockage on the front port. When the brake fluid heated up, there was no room for expansion other than by pushing the caliper pistons. I would like to remove the piston from the old master cylinder, but I was not able to figure out how to remove the circular clip that keeps it in place. Thanks for the help and suggestions.

[MPDano]

Very cool closure.