Power Brake Booster Leak

[adf5565]

I just noticed that I’m getting a leak of power steering fluid from the brake booster right where it bolts to the master cylinder. I just replaced both of these with rebuilt parts a few months ago and have put maybe 15-20 miles on them. Did I just get a lemon of a rebuit booster? Or am I missing something?

 

[cucvrus]

Are you certain that it is power steering fluid. And did you use power steering fluid. I always use power steering fluid. I see guys use ATF and that is not what came from the factory. That is not as thick as Power steering fluid. Another thing that I noticed is that the new brake master cylinders are stamped for DOT 3 fluid and I put DOT 5 in them. Not sure if there is a difference in the seals. Good Luck.

 

[adf5565]

Are you certain that it is power steering fluid. And did you use power steering fluid. I always use power steering fluid. I see guys use ATF and that is not what came from the factory. That is not as thick as Power steering fluid. View attachment 871873 Another thing that I noticed is that the new brake master cylinders are stamped for DOT 3 fluid and I put DOT 5 in them. Not sure if there is a difference in the seals. Good Luck.

Yeah I’m pretty sure it’s power steering fluid that is leaking. I did use DOT 5 for the brake fluid which from Napa has a purple color. The fluid I have leaking is clear and I’ve also had to top off the power steering reservoir. I didn’t use ATF. The leak is pretty significant, with the vehicle started and push/holding the brake for 5 seconds cause it to have noticeable fluid on the underside with a drip or two. I’ve checked hose connections as well and they’re tight with no signs of leaks.

I was able to get a warranty replacement for the booster so hopefully I have better luck with this one.

 

[Keith_J]

Seals for DOT3/4 are fine with DOT5. The purple dye is absorbed into the Seals, turning the fluid yellow.

 

[adf5565]

Seals for DOT3/4 are fine with DOT5. The purple dye is absorbed into the Seals, turning the fluid yellow.

Great, thanks!

 

[adf5565]

I put the warranty replacement in so we’ll see how this one works, so far so good

 

[LT67]

Yeah I’m pretty sure it’s power steering fluid that is leaking. I did use DOT 5 for the brake fluid which from Napa has a purple color. The fluid I have leaking is clear and I’ve also had to top off the power steering reservoir. I didn’t use ATF. The leak is pretty significant, with the vehicle started and push/holding the brake for 5 seconds cause it to have noticeable fluid on the underside with a drip or two. I’ve checked hose connections as well and they’re tight with no signs of leaks.

I was able to get a warranty replacement for the booster so hopefully I have better luck with this one.

Could be your hydro boost unit...

The hydro boost unit on my 86 M1008 has a slight leak and needs to be replaced