Brake Fluid in Driver Footwell

#1

During last Sunday’s race at Watkins Glen I ended up with what appears to be brake fluid in the driver’s side foot well which got all over the bottom of my boots and made pedal work very interesting to say the least.
A quick inspection last night did not reveal any obvious leaks or sources.
Is the next logical step to remove the master cylinder and brake booster?
Is there some sort of lubrication medium in the clutch mechanism that could have leaked?
Both clutch and brake operation seemed fine.
Other thoughts?

#2

One possibility is the soft/braided supply line from the reservoir to the clutch MC, which is part of the pedal cluster.

Mine developed a pinhole leak last year, which became very obvious while I was pressure bleeding it. If you have a pressure bleeder, you could pressurize the reservoir and if the soft line is the culprit, it should kick out a stream you can easily find.

#3

Hi Bob - just a thought: do you still have the heater core in the car? maybe it’s not brake fluid

#4

Yes, I do still have the heater core, but it appeared to be dry and the fluid on the floor definitely had a slick, oily consistency similar to brake fluid.

#5

[quote=“ctbimmer” post=78657]One possibility is the soft/braided supply line from the reservoir to the clutch MC, which is part of the pedal cluster.

Mine developed a pinhole leak last year, which became very obvious while I was pressure bleeding it. If you have a pressure bleeder, you could pressurize the reservoir and if the soft line is the culprit, it should kick out a stream you can easily find.[/quote]

Thanks. I do have a pressure bleeder. I’ll hook that up tonight and see if I can see anything.

#6

Pressurized the brake system last night and did not notice any new visible streams of fluid.
Also ran the car and circulated water through the heater core and did not see any noticeable leaks from that system.
Put the car up an jacks and noticed similar fluid on the steering knuckle and frame rail that are directly below the master cylinder/brake booster assembly. The lower section of the booster also appears to “wet”. I think the fluid may have come in through the wire harness pass through in the firewall as there appears to be some corrosion there and the rectangular rubber grommet is not completely sealed. It may still have something to do with the hose Chuck mentioned because the end of it disappears into the firewall at about the same area of the grommet, but the section of the hose that is visible appears to be fine.
I guess my next course of action is to remove the brake booster…

#7

Before you do that you should check the fluid resevoir cap. They love to leak, especially if the res is a little overfilled.

#8

Do you have a vent hose on your transmission? Any chance some transmission fluid spewed out of the hose?

#9

I didn’t notice an issue last night, but wasn’t specifically looking at the cap either. Will give it a closer look tonight.

#10

I did…but that’s a good thought. Maybe it came off. I’ll check that as well.

#11

Ok. I think I found the source of the fluid. Thanks to Ed’s suggestion I checked my transmission overflow hose. The transmission end was still attached but the other end had fallen down and was laying behind the brake booster. The end of the hose was dry, but the area right around it was still “wet”. So it must have been transmission fluid and not brake fluid.
I will be putting a catch bottle on that end before the next event.
Thanks for all the suggestions.