View Full Version : Brake leaks only when pump runs.

03-21-2011, 08:14 PM
My brakes leaks fluid only when the pump motor in running.
Start the car and I hear the pump mortor and under the car is a puddle of fluid.
When the pump stops, so does the leaking.
I have to wait until the system depressurizes before it will leak again.
I know there is a gasket between the pump housing and the ABS Master cylinder.
Does anyone one know where a repair kit or a new/rebuilt pump motor with gasket or parts can be bought, like the gasket?

Mike Puckett
03-21-2011, 08:49 PM
I have a friends that's doing the same thing. Check to see exactly where the leak is coming from. His is the pressure sensor. I also removed the bottom screw on the pump and put sealer on it and tightened back up. That didn't stop it. Then I stuffed a wad keenex into the space around the sensor and it stopped dripping until it saturated and stared to drip again. The sensor is the green cylinder with a hex around it for a wrench. You can see the whole thing from underneath and get to the pump bolts. They are allen head screws. I did search and found that it's a 36mm deep socket to get the sensor off. I'm hoping my friend's just needs to be tightened up and I'm hoping we won't have to remove anything to put a wrench on it. The sensor is sealed with an O'ring.

03-22-2011, 12:26 AM
There is a small 5.5mm seal on the front of the pump motor.....

When it fails, it allows brake fluid to enter the pump motor....

It leaks out the vent hole located on the bottom side of the pump motor....

03-22-2011, 06:03 AM
OK, seeing the pump seal, now it makes since. I can hear the difference in the sound of the pump. Almost sounds like a death rattle.
What would be the best way to get this fixed?

03-22-2011, 08:44 AM
Pump motors can be rebuilt....:D

I have a local guy rebuild them for me....

I have a freshly rebuilt motor on the shelf ready to ship....

03-22-2011, 08:50 AM
This is for an 89 - 90 Brake unit?
And how much $$$ ???

03-22-2011, 03:33 PM
Yes, it will fit those years....

I'll need a zip code to figure shipping costs....

03-22-2011, 03:38 PM
here you go.