I have been loosing bake fluid from the rear system, not sure if it is coming out of the master cylinder reservoir or somewhere else. do not see any fluid at wheels or the lines but light comes on and the front smaller brake flui9d reservoir is very low. Any ideas guys?

 

Does it look wet anywhere? Maybe you'll have to take the drums apart.. but you'd be able to tell if brake fluid was leaking.. looks like wet rust.

 

IIRC you need to check the bottom of the booster as well. Run your fingers along the lowest portion and see if they come up wet. If they do the master cylinder is shot.

 

Mine did the same and it was the rear wheel cylinder (left side IIRC). NEVER saw so much as a drop of fluid externally but once I removed the drum....YUUUCK! Brake fluid/brake dust paste mud everywhere.

 

Totally rebuilt the back brakes, new wheel cylinders pads adjusters springs, added a new rwal valve and all new parking brake cables. everything was fine but rear brake system lost all the fluid in the front reservoir in about two weeks. have it at dodge dealer looking for other leaks. Why do I always get the feeling when I have them look for something that I know more than they do?

 

Time to stop going to "them". Personal experience I've had is that when they see me coming, they see $$$ signs Old truck... lots of repairs. This is why I spend so much time here reading, as I'm tired of being taken advantage of.... so I do it myself.... kind of like being married for 25+ years


Sometimes the master bleeds internally between both reservoirs, or so I'm told, but I've never experience it in reality.

Every time I've ever had this missing fluid issue, it's been in the rear wheel cylinder dept, , or the brake hose bolts weren't tight enough on the front calipers, or wheel cylinder leaks of some sort...which led to the paste / brake dust mentioned before

Best thing to do is to crawl around under there and search. Bleed the brakes and drive it for a couple days, and search again. You'll eventually find it.

 

Brake Fluid



Break Fluid

 

Is the outside of our master cylinder wet? My 93 started loosing fluid from the rear reservoir of the master cylinder and pushed it into the front side. There was an internal leak. Drover me nuts for a while until I noticed the outside of the cylinder was stained with brake fluid. At first I thought it was where I had spilled it before I realized what was going on. Replaced it, no more fluid loss.

John

 

I was thinkin the small res. was the disc on front. But could be havin a brain fart.

 

Last week I backed my 90 out of the barn...no power brakes and the brake and ABS came on. It was leaking a large amount of brake fluid. Apparently for some time it had leaking back into the brake booster until it ruined the diaphram inside the booster then it all ran out at once. I obviously had to replace both the master cyl. and the booster. They were suprisingly inexpensive.

 

What's ya doing Willis ?


Are jew da nu gramaticel plrofessor on campuss ?

 

Small resevoir is for rear drums, big res. for discs.

 

Picked up truck yesterday, they bled the brake system and replaced the rubber cap seal on the master-cylinder. first call from them after 1 day when they finally got to look at it was that when the technician was test driving the engine died and he could not get it started. had to tell them to check the power connection on the fuel cutoff solenoid. I told him that after 9 years of driving I have never had the wire come off but have forgot to put it back on when adjusting the fuel screw. second call said that they would need to need the system to test. and they adjusted the right rear but could not adjust the left rear brakes. said they would have to take off drum to look at it I said no thank that I just rebuild the brakes two weeks ago and was not worried. Official diagnosis was that the cap seal must be the cause of the leak. when I got home I checked the adjustment of the rear brakes and took me a total of 2 minutes to adjust the left rear brake, go figure. I will see if fluid disappears in two weeks again. I cleaned everything off again with brake cleaner and will keep an eye out for leaks, but my guess is that the front piston seal in the master cylinder is leaking into the rear (front disk brake and then overflowing the larger reservoir.

 

J. You drink some weird beer man! Well besides yellow bellies, those are great!

To the op. Pull the master off the booster. I bet the booster is full of fluid. You will need to replace both of them.