Jump to content
  • When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

master cyl leak into intake?


Guest Anonymous

Recommended Posts

Guest Anonymous

I have ahd crazy problem getting my 02 to run smooth, finally brought to mechanic and after many hours of checking everything he has decided (after I mentioned that I read something on this board) that the master cyl is leaking and brake fluid is being sucked up into the intake and causing smoking and rough running. Now he wants to replace master cly and inorder to blead system properly I need new wheel cyl's (as bleeder is seased) This is all going to cost a hugh amount!! does this sound like it could be the? The brake fluid resovior is down but not that much...if it was causing the rough running would'nt I be loosing tonnes of brake fluid? carb checked out ok!! and lots of spark

Link to comment
Share on other sites

Guest Anonymous

Troubleshoot it by disconnecting the vacuum hose from the brake servo. Cap the hose well or you will have one heck of a vacuum leak. Take care when driving the car as the effort to apply brakes will be a bit more. If the problem is still present, the m/c is not the problem. The servo vacuum hose is the only route for the brake fluid to travel to the intake side of the engine.

Earl

74 2002Lux

72 Volvo 1800ES

Link to comment
Share on other sites

Guest Anonymous

I sucked about 20oz of brake fluid out of my booster! With my car, the engine ran great all the time until I drove over a large bump or incline, then the engine would stumble quite a bit and huge amounts of white smoke would pour out the tailpipe. There will be no mistake that the fluid is getting burned when it comes out the tailpipe! I would also think that for the engine to run so poorly that you would definitely see a cloud out the back when it happens, and you'd also lose quite a bit of fluid.

Do as Earl suggested and pull the vacuum line off between the manifold and booster. I did this and the smoke cleared up within a couple miles.

When I say there was a lot of smoke, I mean there was a LOT of smoke. I filled the entire overhang at an Arco gas station full of smoke the last time it did it! People were jumping back into their cars thinking that it was going to blow!! 8-)

Link to comment
Share on other sites

Guest Anonymous

from the booster into the intake manifold, one (or both) of two conditions have to be present:

1. A brake booster can has filled up to the vacuum port with fluid to the point where engine vacuum sucks up fluid (the booster can has a LOT more volume than the fluid reservoir - to fill the booster can to the vac port would require multiple top-ups of the reservoir over a period of time).

2. A booster can partially full of fluid AND significant cornering forces that push the fluid up the side of the can to where they reach the vac. port.

Number 2 is how is how my m/c to booster leak revealed itself - every time I'd take a fast, tight left turn at speed, there'd be the same HUGE cloud of white smoke Dan described in his post, frequently accompanied by loud knocking. When the m/c was removed, the booster can was found full to about 12mm below the vac port which provided enough fluid for it to slosh up the right side of the can to the port on hard, fast lefts.

If you're careful, you should be able to remove the m/c to booster stud nuts, pull the m/c partially away from the booster can, and slip a long pipe cleaner or strip of posterboard as far down into the can as possible - if it comes up wet with fluid, you've found your leak.

Link to comment
Share on other sites

Guest Anonymous

Thanks for your advice!! ya the mechanic wants to charge me $2000 to change my master cyl (which according to him includes all new lines, wheel cyl and calipers)oh well...I'll pick the car up today and drive it around with the vacume line plugged..if the smoke clears I'll replace my own master cyl.. thanks again

Link to comment
Share on other sites

Guest Anonymous

That's outrageous! My mc was leaking into the booster as well. No smoke though. It's an easy replace, but you have to get that crap out of the booster. That is the part that sucks because removing the booster is a pita. But-it's very doable with conventional tools and a couple of spare hours.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Upcoming Events

  • Supporting Vendors

×
×
  • Create New...