ABS & Brake lights on; Master Cyl leak

[MAX A/C]

Well, my faithful truck seems to have become broken! After the truck sat for a week, I noticed a leak of brake fluid, apparently coming from between the brake master cyl and the vacuum booster. Noticed it because the left front leaf spring was coated with fluid. Shortly after start up, the ABS and Brake idiot lights came on and stayed on. Brakes still work, but there's a problem that must be fixed now. Suggestions anyone? Could it just be a seal that went south?



I will have a shop do the work, but I don't want them to sell me parts I don't need!

Thanks in advance.

Scott

 

[JLEONARD]

When I bought my truck last summer, there was the witness of a dribble from between the booster and master cylinder but nothing below was soaked.

Since I was replacing the front calipers and pads, and had to replace everything in the rear including drums, I decided to put in a new master cylinder as well.

I had the brake warning light come many times... . sometimes it would stay on for days. Sometimes I would disconnect the battery terminal to re-set it.

The brakes always felt fine, and even when I locked them up in sand or wet roads to check the anti-lock system, it always seemed ok.

The brake light rarely comes on now, and always re-sets itself overnight. I think because the truck is now driven daily (previous owner put on only 1000 miles in a year) the system is working better, mainly the rear axle proportioning valve, which I think was sticking and causing the brake light to come on.

 

[Old Smoky]

My ABS and brake light, on the dash, also come on. When I am stopped with my foot on the brake for more than about 30 seconds or so they come on. After taking my foot off of the brake the lights go out almost immediately. I don't think my Anti Lock Braking System is working. My brakes lock-up. Snow, ice, mud, gravel, pavement, it doesn’t matter. The right rear is the most prone to lock-up. What do you guys think?



Mike

 

[Dfeland]

You have a vacuum leak. Probably it is your brake booster. Only about $75 and a half hour to change. That seems to be the most common thing. There is a switch under your hood by the heater grid contactors that is round and if the vacuum drops below 8in then it turns the lights on. So when you pull away from a stop the vacuum pump produces enough vacuum to compensate for the leak.

 

[JLEONARD]

Smokey, I agree.

You have a vacuum leak.

 

[Old Smoky]

Thanks for your help guys! I will have to check that out.



Mike