Chevy & GMC Vans

2000 Astro AWD (had it since I drove it off the showroom floor), 172,000 miles. I plan on being buried in my Manship. Developed some kind of brake fluid leak from master cylinder (reservoir nearest the firewall drains to nothing, reservoir nearest the radiator stays full). Fluid drains by itself onto a piece of cardboard at a place near the right front fender, between the fender and the radiator ( car is in driveway at about a 10 degree forward tilt).

I have looked all over the net for a line diagram of the brake system and can't find crap! My super-powers of deduction inform me that it is probably a leak in the steel brake line (which then connects to the flex line going into the brake cylinder on the right wheel)? I see only 2 lines coming from the master cylinder and they both disappear towards the rear of the ship.

Without messing up this post with all my screwball theories.........has anyone:

1. Had this problem and have a theory (my last resort).

2. Had this problem and found a solution (you're my hero)

I think I need a hug.............

Welcome!

Sorry I don't have any technical advice to contribute, but this is a great first post. I especially like the signature and reference to "manship".

I also have a 2000 AWD but with 150,000 miles. 40k in the last 3 years of my ownership.

Got pics?

I am greener than the grass on this site and can't find a place to attach a photo of "my baby".......(as the girlfriend calls it).......I have a photo from the front, but the girlfriend is in the way and distracts from the full beauty of this awesome machine.

They're both lookers. I've always liked that green colour.

Theres a few site regulars here that are from Washington too.

By the way, how are your front wheel bearings holding up?

Welcome to the site. You have a great sense of humor. Here's my best guess on the problem. Both of the steel lines that disappear under the firewall from the master cylinder go to the ABS/Proportioning Valve module. From there they go their separate ways to each wheel. I would start at that module and follow the line to the right side and check for a leak somewhere. You might have one of your kids apply pressure to the brake pedal while checking. It might help you spot the leak. Good luck. Let us know how it works out.

Thanks for the welcome fellow Astrofans. I will crawl under and take a look from the ABS module towards the front where I "think" the leak might be occurring. It's like having a leak in your roof...........you noodle around where you think the leak is...and it turns out the leak originated at the other end of the house! ARGHHH.

My front bearings seem fine......but please......I am already losing sleep over this brake issue. ](*,)

I replaced the hard brake line to the front right on Grumpy. It's a long line the wraps around the front of the van. You can see it in front of the front cross member. If you need to replace it, you'll most likely need to buy a roll of line. Cutting, bending, and flaring wasn't that hard. Installing the bent tubing can be a little bit of a pain.

Thanks for the tip Aaron.....I will take a look. Do you know why the master cylinder drains the rear reservoir and not the front reservoir? Does the rear reservoir go to the front brakes......just wondering?

John

I think that's the way it works, not certain though.

After working on Green this weekend I can say without a doubt that the rear reservoir is for the front brakes.

I know that when I had a leak in my line going to the back brakes a few yrs ago the front res was empty.

Okay guys........here is an update:

After waiting many days for the monsoons to cease and my ambition to increase...........

I found the leak. It is a tiny pin prick of a hole (looks like it was caused by electrolysis) just to the right and down on the frame from the blower. I can get to it (not really....but kind of) after removing some of the air cleaner pieces.

I hate doing things half-assed.......but has anybody been able to solder, or braze a hole in steel brake line with any success? I may be out of my mind to think that this would hold under "extreme" circumstances such as dynamiting the brakes in an emergency?

I am pretty much expecting the "finger wagging"....with the advice: "just replace the damn line"!

It's okay to ask, right?

Got to change the line properly. Here is a picture of a 2WD subframe, if you look closely you can see where the line goes. Yours will be similar I believe but not exact. Not a bad job to do, but I did it while the van wasnt in the way! If you keep in mind your new line doesnt have to be bent perfectly like the old one it will go much easier!



Scott

Heres the new line in:

A picture is worth a thousand words.....(some of them four-lettered)....and many broken and bloodied knuckles. Thanks for posting that photo.