suburban brakes?

Reply

  #1  
Old 03-10-02, 12:40 PM
tmhunter
Visiting Guest
Posts: n/a
suburban brakes?

I have an '88 Suburban that was having a problem with the front brakes locking up before the rears even engaged. I changed the front brake pads, adjusted the rear pads (pads are o.k.), replaced the combination valve (some people I've talked to called this a proportioning valve), and then went to a new master cylinder. We went to the new master cylinder after noting far diminished flow from the front port on the master cylinder, and the rear brakes bleeding very slowly. When we open the bleeder valves in the rear, the fluid slowly oozes out and the brake pedal doesn't go to the floor, compared to the normal squirt and the brake pedal going to the floor. I opened the line at the T above the rear differential with moderate fluid flow, and opened it at the coupler midway down the frame, again with moderate flow. I've exhausted all my ideas (although I am a novice), and I am desperate for any ideas that you all may have...thanks.
 
Sponsored Links
  #2  
Old 03-10-02, 01:00 PM
marturo's Avatar
Member
Join Date: Jun 2001
Posts: 1,448
It's a long shot. however a deteriorated rear rubber brake hose has been found to cause an internal restriction. When bleeding your rear brakes the petal will not go all the way to the floor it stops half way.

I have run into brake systems where people who ran dot 3 or 4 and did not flush out the system every year. Their was so many rubber particles in the system that these pieces acted like plugs throughout the system.

I would be surprised if it were your proportioning valve. The 2 front and 1 rear rubber brake hoses are often forgotten when people service their hydralic systems. They can cause some strange problems if not replaced for long periods.
 
  #3  
Old 03-10-02, 03:14 PM
Member
Join Date: Jan 2001
Posts: 93
Lightbulb

I agree with Marturo. Its probably the rubber hose is bad. Also dont forget to replace the brake fluid. Good luck on the repairs. keep us posted.

OM
 
  #4  
Old 03-10-02, 09:34 PM
Member
Join Date: Mar 2002
Location: Louisiana
Posts: 438
I own a '89 Burb and the rear brakes have always been a pain in the A**!
When you bleed the rear slve cyliders, you have to press the metal button on the porportioning valve. The best way that I've found to do this is with a 6" C Clamp. It's kind of difficult but it can be done. You should notice a better flow on the back bleeds with this button pushed in.
The rear brakes on my Suburban will not keep self adjusted. The design is that they adjust when hitting your brakes in reverse. I've had several mechanics look it them (thinking I've missed something) with no improvement. I've had other mechanics tell me there really is nothing that can be done other than to set the parking brakes every time you park. I've done that and it seems to prolong the pedal play for awhile but it seems like I still do a manual adjustment every six months or so.
 
  #5  
Old 03-11-02, 08:36 AM
Joe_F
Visiting Guest
Posts: n/a
I agree with all written here.
 
  #6  
Old 03-11-02, 06:19 PM
rickwhoo
Visiting Guest
Posts: n/a
if the truck passed the state inspection dont worry about it as long as the truck stops. the rear brakes should not lock-up at all when panic stopping.
 
  #7  
Old 03-11-02, 07:39 PM
Joe_F
Visiting Guest
Posts: n/a
Thumbs down

NYS state will also pass you:

1) If your shocks are there, but blown out
2) If your side window is shattered but there is no jagged glass.
3) If only one of your two backup lights works
4) Even if your license plate light doesn't work
5) If you have more than a Lincoln's head's worth of tread depth.

Fact is just because it makes it through inspection it doesn't mean it's 100% safe. It just means it meets the minimum requirements.

Do your own safety and repair analysis. Don't rely on the state!
 
  #8  
Old 03-11-02, 07:44 PM
Member
Join Date: Mar 2002
Location: Louisiana
Posts: 438
The Suburban in '88 is designed for all brakes to lock in a panic stop. It is a towing vehicle. ASB may have been offered as an option but was not standard equipment. It is a heavy vehicle and as an owner of a Suburban, I would not drive one without rear brakes.
 
  #9  
Old 03-12-02, 09:40 AM
rickwhoo
Visiting Guest
Posts: n/a
try to panic stop any vehicle and get out and look at the skid marks. you will only see front tire skid marks. if the rear wheels locked up you would spin out of control. the rear brakes are there to assist in braking. the state inspection inspects safety issues like brakes, lights, wipers, etc..
 
  #10  
Old 03-12-02, 11:59 AM
Joe_F
Visiting Guest
Posts: n/a
Rear brakes should still work and be safe though .
 
  #11  
Old 03-12-02, 07:05 PM
cheese's Avatar
Forum Topic Moderator
Join Date: Jul 2001
Location: USA
Posts: 16,575
The state may say "OK...you have brakes....good enough for us." But they don't drive the car everyday...you do. Yeah, you might have brakes, but if you can tell they're not functioning quite like they should then that should not be acceptable. Brakes are not one of the places to cut corners.
 
  #12  
Old 03-13-02, 07:34 AM
rickwhoo
Visiting Guest
Posts: n/a
like i said before, rear brakes are not supposed to lock up..
 
  #13  
Old 03-13-02, 09:15 AM
Joe_F
Visiting Guest
Posts: n/a
Right.

However, you've stated that as long as you pass inspection you're ok.

I wouldn't want to rely on the state to tell me what's "safe". They are giving the MINIMUM requirements. Your inspections should be much more comprehensive than that.

Rear brakes should work right. That's what we are all saying here .
 
  #14  
Old 03-14-02, 08:16 PM
tmhunter
Visiting Guest
Posts: n/a
thanks for the info guys; I finally bled the brakes properlly by holding the pin in on the compensation valve, and they are now working better, not great but better.
 
  #15  
Old 03-15-02, 12:47 AM
Member
Join Date: Mar 2002
Location: Louisiana
Posts: 438
"Better" is as good as it gets on those old busses!
 
  #16  
Old 03-15-02, 01:28 PM
Member
Join Date: Dec 1999
Location: Cleveland, OH USA
Posts: 508
Brakes are a known problem

Having followed another forum dedicated to Suburbans (http://forums.vmag.com/suvsuburban0102), the brakes on these Pre-2000 models are not bad but do require regular attention. Most of the recommendations I have seen say that the rear brakes should be adjusted at each oil change and will probably outlast the fronts by 3-4 times. The "auto-adjusting" done when backing up and stopping actually requires some pretty agressive backwards driving (they say kids love it) - but overall don't count on it happening automatically. Using the parking brake does not significantly adjust the rears on these vehicles.

You can also take a look at this site for more maintenance and repair tips for Suburbans: http://subtopics.freeyellow.com/subtopics.htm
 
  #17  
Old 03-15-02, 05:52 PM
marturo's Avatar
Member
Join Date: Jun 2001
Posts: 1,448
GM self adjusting rear brakes

My son who is 26 and loves to adjust his C/10s rear brakes. He gos part way up a hill and rolls backwards and slams them on about 6 or 7 times. I am 50 and just take my brake adjusting tool at every oil change. Self adjusting LOL, whiplash specials. Every GM I ever owned, no mater what lube you use.
Marturo
 
Reply


Thread Tools
Search this Thread
Display Modes
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -7. The time now is 03:06 AM.