Hello,

I figure I have a MC problem with my 92 Tracker so I bought a used one and am going to change it out. I am going to bench bleed it and am confused about something; can anyone break down the MC various components and answer one specific question?

I have attached a picture of the one I have in the vice right now. Since I didn't have a bleed kit, I used some of the hard lines from the one I took out to hook up to the new one, then added some tubing I had on hand to put into a bottle with fluid in it. First off, when I bleed it, should I expect to have fluid come out of 2 or 3 outlets? I tried a little last night (just to see) and fluid only came out of the one marked with the yellow arrow. I expected it to also come through the other red arrow marked tube but nothing came. I didn't try it for terribly long because I didn't have new fluid yesterday but I bought some today and am going to try now. I don't want to put it back in if this might be a sign that the new MC isn't functioning properly.

Any help is appreciated. If you need better pictures, let me know.

Thanks.

Ok I went down and had another go at it. The inlet on the opposite side started squirting. So is it 2 or 3? Here's a picture of the one I mean now..

Regardless of how many outlets you see, the master cylinder has two sections - front & back - once you can get fluid from both sections, the master cylinder itself is probably good - I can't say the same for the maze of plumbing you have surrounding it.

Trying to make sense of the plumbing, the master cylinder appears to have two ports on the front section, both visible in the second picture, and one port on the rear section, visible in the first picture.  You appear to have some device hanging off the side of the master cylinder in the first picture that I have never seen before - possibly RWAL (rear wheel anti lock).

I took a look at the Sidekick parts catalog - that device is some sort of pressure limiting valve - it's not part of the master cylinder perse - I can't tell you how it affects your problem (because I don't know the symptoms of the problem), however, if you removing the plumbing, you can do a quick check of the master cylinder like I describe above.

Ya I think I over (or under) thought it. I disconnected the MC from the combo valves and rigged it up to have 3 lines pumping back into the reservoir for bleeding.

I am a bit curious as to how that RWAL works. It has a bleed nipple on it. At what point would I want to attempt to bleed it or at all?

I am a bit curious as to how that RWAL works. It has a bleed nipple on it. At what point would I want to attempt to bleed it or at all?

That I have no informed answer for - I've never seen RWAL, it wasn't fitted to the cars we got here.

You probably need to bleed it at some point (why else would they put a bleed nipple), and I'm thinking that you WILL need to bleed it for the job you're doing - if had access to a brake diagram that showed the plumbing I could probably figure it out.

Once you've drained the system, the general rule is furthest from the master cylinder first and then work your way to the closest, if the RWAL is anything like the LSPV (load sensing proportioning valve) used on my GV, the bleed nipple will be on a front brake circuit, so that would get bled as the third item - making the sequence something like this - furthest rear, closest rear, RWAL, furthest front, closest front - BUT - I am just guessing.

So changing the master didn't solve the problem.

I guess I never mentioned the problem.. Here it is..
When you hit the brakes the pedal goes right to the floor, the light comes on and you can pump some life back into them occasionally. While not 100%, the pads, drums, rotors etc are fine; the ebrake holds well. To me, all signs pointed to the master. I bench bled the master and then reinstalled it and started bleeding at the driver side rear and the pedal had some good stiffness. There is no spot to bleed on the passenger rear so I moved to the passenger front, after a couple of pumps the pedal turned to crap again!

Any ideas??

Two questions - what is the light that comes on - and - are you losing fluid anywhere?

The light on the instrument panel that indicates a master problem and no fluid loss at all.

I've never seen the manual for a 92 Tracker but I'm going to go out on a limb and say there is no light on the instrument panel that indicates there is a master problem - find out exactly what the light means.

If I'm right there is one switch on the master cylinder and that controls the low fluid light - there appears to be one or more switches on the plumbing in your pictures - so the light you refer to MAY be driven from one of those, so it may indicate a failure in the RWAL system, or a loss of pressure in a brake circuit (assuming the Trackers are fitted with a dual circuit braking system.

I think you're going to need to figure out what that plumbing is for and does before you can make headway.

Sounds like there's still air in the system.  There's also a high bleeder screw by the master cylinder, I believe, behind the horizontal arrow in your first photo.