Brake fluid in the exhaust

[Ender]

Can brake fluid get into the exhaust thru the power brake booster? The vehicle is a 91 Pathfinder. I know it's not TD but I was hoping for some insight . The past couple of days it's been blowing a cloud of smoke out of the exhaust but only occasionally. It is definitely brake fluid burning. I know the smell. I'm wondering if a bad booster/master cylinder would allow fluid to reach the intake. Any ideas?

[55trucker]

IMO thats an extreme longshot. For that to take place....1. your rear seal on the master cylinder would have to have failed.(allowing fluid to leak between the master and your booster, as such , your fluid level would drop.) 2. your booster would have see the front piston seal on the vacuum side fail as well..allowing vacuum pressure to be drawn directly from just behind the master cylinder (which would probably affect your overall brake pedal pressure)..theres no positive seal between the booster & the master allowing negative pressure there......If you truly believe that you've got brake fluid getting into the engine(it has to be burnt off before it goes out the exhaust manifolds, and I would think that would affect your engines running)...try this....block off the vacuum port on your intake that feeds the booster (you won't have booster application), but it should let you know if indeed you've got fluid being sucked in by that route (take a flashlight and peek up the tube to see if the inside is wet).

[Ender]

Thanks for the reply. It's not actually my truck, but the guy who owns it is a good wrench and knows what he's talking about. He did say that he was losing some fluid, but I don't know how much. As I said, the smoking is intermittant, almost like the fluid builds up to a certain point then goes all at once. He said that when it smokes it smokes ALOT, enough to scare his kid out of the truck I'll relay the info to him tomorrow at work and see what happens.