Transmission Fluid in Brake Master Cylinder

find the dummy and beat his ass.. then make him pay for your new braking system

I did not see if you have abs brakes, if so, the abs unit is likely a problem.

Otherwise, it would probably be easiest to just replace all four calipers, turn or replace the rotors as needed. You could try taking the calipers apart and cleaning with brake cleaner, but thats a low buck method with a minimum chance of success.

The master cylinder is also inexpensive enough to change.

You also change the combination valve, but I would initially just pull it off by itself, and flush the heck out of it with spray brake cleaner.

Then flush all of the lines you can with a bunch of brake fluid.

Then I would collect the costs from the so and so and then have him beat.

Man that really sucks. A good friend of mine once bought a 90 park ave off another not so smart friend who had put ATF in the brake system because he thought it was the same as brake fluid. It ate all the rubber seals out of the calipers, slave cylinders, and master. We pretty much had to rebuild the entire brake system. That really really sucked. I feel your pain man.

J.

Almost the same happened to me. The funny part is that somone put apparently power steering fluid in the master cylinder and my brakes didn't exactly lock up but something funnier. If you know what ATF/power steering fluid does when it heats up - it expands. So the more I drove around, the tighter and tighter the brake engaged as I drove. But I could go out the next morning and repeat it all over again with no initial brake problems

I had to replace the master cylinder and had my brake system "chemically treated" whatever that meant and flushed heavily. That seemd to solve it completely though.

Anytime a fluid with seal swelling agents such as ATF contaminates your brake system, everything that is rubber MUST be replaced. That means calipers, wheel cylinders, prop and metering vavles, master cylinder and if abs equiped, the unit will likely fail and you will never be able to remove all atf from the unit anyways so it should be replaced. lines flushed with fresh brake fluid. Any rubber component will soon leak if not replaced. good luck.

You may find this useful...

Garden Sprayer Pressure Bake Bleeder

1 each pump type garden sprayer, 1 - 1 ½ gallon capacity (size doesn’t matter much, it just has to be cheap and small enough to be easy to work with)
6-10 feet 3/8” clear plastic tubing
1 each ¼” brass pipe tee
1 each ¼” pipe to 3/8: hose adapter
1 each pressure gauge 0-60 PSI or so – all you’ll ever need is 5- 10 PSI, so the gauge range doesn’t have to be high.
1 each large rubber stopper – this is the hard part to find. It may take some searching to find one that is a snug push fit to the inside of the filler port on the master cylinder. You can use silicone rubber to seal a brass fitting to an old master cylinder cap, but they tend to leak too much.
Home Depot or Lowes has some ¼” brass pipe stock that is continuously threaded in the electric lamp repair department, along with the brass nuts that go with it. This is better than a pipe nipple, since the nuts can be used to secure the pipe in the cap or stopper.
OR if you can’t find the threaded pipe stock,
1 each ¼” nipple, 1 ½”- 2” long

The rubber stopper needs a hole drilled in it for the ¼” pipe nipple or threaded pipe stock. After you drill the hole, use some silicone gasket sealer to seal the pipe nipple as you push it into the rubber stopper. If you used the threaded pipe stock, use the nuts to secure the stock into the stopper.

If you can’t find a suitable rubber stopper, an old master cylinder cap can be used. Drill a ½” hole in the center for the pipe fitting. Cut the brass pipe stock to about 1”- 1 ½” long, the exact length isn’t too important. Push it through the hole in the master cylinder cap and thread one nut on top of the pipe stock where it sticks though the cap. Put another nut on the other side of the cap to lock the pipe stock in place. Apply some silicone rubber gasket sealer to both sides and when it is dry, screw the ¼” pipe that sticks out of the top of the cap into the tee.

Remove the sprayer hose and wand from the garden sprayer. You may find it easier just to cut the sprayer hose off short and connect it to the 3/8” plastic tubing. The idea is that the 3/8” tubing connects to the pickup tube inside the sprayer in a reliable, leak proof fashion. Another alternative is to remove the spray nozzle from the end of the spray wand and connect the 3/8” tubing to the wand. This leaves the hand valve in place and may be useful to start/stop the flow of brake fluid.

The 3/8” plastic tubing connects to the pipe tee using a push on hose barb type adapter. The pipe tee has one port for the gauge, one for the 3/8” hose and the other to connect to the rubber stopper or master cylinder cap that you modified.

Fill the pump sprayer with a quart of brake fluid. Set the garden sprayer on the ground and screw the pump handle down tight, and pump until brake fluid fills the plastic tubing. Then put the modified stopper or master cylinder cap on the master cylinder and pump slowly to make sure that nothing leaks or pops loose. No leaks, continue pumping until you get 5-10 PSI. Put a 6”-12” length of clear plastic tubing on the bleeder ports. Then open the bleeder ports on the wheel cylinders one at a time and bleed until the bubbles are gone. I use a 2 liter soda bottle with a coat hanger to catch the fluid . DO NOT REUSE THE OLD BRAKE FLUID. Repeat the process until you have finished all 4 wheels. You will have to pump the sprayer several times to maintain the 5-10 PSI needed to do the job. When finished bleeding, loosen the pump handle to relieve the pressure, remove the stopper/modified master cylinder cap and test the pedal.

"....and see what happens."

This approach is rarely a good idea - it's a PARTICULARLY bad idea when it comes to brake work.

It's almost free to try a good bleed. Buy several large qt. cans of brake fluid. Take a $.99 turkey baster and suction as much out of the resevoir as you can, but not all the way to the bottom. Then fill the resevoir with fluid, and pump it through to one of the front calipers - the larger front lines make it go more quickly. I'd run 2 or 3 resevoir-fulls through to be sure the resevoir has only brake fluid in it. Be sure not to completely empty the resevoir at any time. Once that's done then run a good pint through each of the other 3 calipers. Take it for a VERY careful test drive - stay as much away from others as you can, speeds down til you see how it behaves. If it seems normal - try to get out to a location where you can do some higher speed hard braking. Remember - if seals are weakened - it can be fine until you hit it hard, then you can lose the brakes - so be sure you have the room to safely stop it otherwise.

Inquiring minds want to know - how did ATF get added to the resevoir? Usually, they are so full that only a little bit could be added before overflowing the resevoir.