Reply
 
Thread Tools Search this Thread Display Modes
 
Old 11-08-2009, 07:58 AM   #57
Full Timers/Diesel power.
 
Mike Leary's Avatar
 
1983 31' Airstream310
Cactus Hug , Arizona
Join Date: Mar 2007
Posts: 2,540
Images: 11
Quote:
Originally Posted by MaryContrary View Post
Mr Mike Leary, i think we just passed you in Flagstaff...!@#!
That indeed was us, sorry to miss you! Were you on 66? We're headed south, but hanging north until the weather cools; northern thick blood, you know. Send us a pm if you're in the area.
__________________

__________________
"A settled wisdom, plus the itch to be elsewhere"
Mike Leary is offline   Reply With Quote
Old 03-19-2011, 06:25 PM   #58
Athens GA
 
Myrtle lynn's Avatar
 
1995 28' Excella
1989 34' Excella
1986 31' Sovereign
1987 34.5' Airstream 345
Athens , Georgia
Join Date: Dec 2007
Posts: 578
Images: 4
Ok. Have my 87 345 in shop for 2 months with hydro boost problems. Has there been an update for this thread since 2009? I am going to relate the post from this thread to them on Monday. I was just checking if there was an update. Thanks for any help.
Dan
__________________

__________________
Athens GA
Myrtle lynn is offline   Reply With Quote
Old 03-20-2011, 12:34 AM   #59
3 Rivet Member
 
1983 31' Airstream310
Santa Cruz , California
Join Date: Sep 2008
Posts: 157
Images: 12
For the full report on my brake problem see
http://www.airforums.com/forums/f159...-td-70005.html

It has stayed fixed :-)

I learned more about this brake system than I ever wanted to know. Alignment between the hydroboost and the brake cylinder is critical. Does your 345 have a Mico Lock or any other difference from the stock system? What problems are you having?
__________________
dljosephson is offline   Reply With Quote
Old 03-20-2011, 03:36 PM   #60
Hypnotist
 
jjhypnotist's Avatar
 
1982 28' Airstream 280
las vegas , Nevada
Join Date: Jul 2007
Posts: 47
These repair shops want to argue all day long however If the hydroboost has been replaced then it is not the issue...
I went through hell with mine too The master cylinder must be shimmed out to the right distance or it will slowly but surely activate the brakes..
Once I had mine fixed I never had another issue with it.....

The lock up issue did cause parts in the transmission to wear out prematurely though.
Justin
__________________
jjhypnotist is offline   Reply With Quote
Old 03-20-2011, 06:23 PM   #61
Athens GA
 
Myrtle lynn's Avatar
 
1995 28' Excella
1989 34' Excella
1986 31' Sovereign
1987 34.5' Airstream 345
Athens , Georgia
Join Date: Dec 2007
Posts: 578
Images: 4
Thank you both. I am going to drive out there tomorrow to check in. If I understand they are locking up on them. I will post tomorrow after I talk with them. Thank you again! I just want the damn thing back. Haha. I miss her.
__________________
Athens GA
Myrtle lynn is offline   Reply With Quote
Old 03-22-2011, 09:15 PM   #62
Athens GA
 
Myrtle lynn's Avatar
 
1995 28' Excella
1989 34' Excella
1986 31' Sovereign
1987 34.5' Airstream 345
Athens , Georgia
Join Date: Dec 2007
Posts: 578
Images: 4
Yep. It needed to be shimmed. But let me tell you tag axle, breaks now work, all new lines, calipers, pads. Stops great!
__________________
Athens GA
Myrtle lynn is offline   Reply With Quote
Old 03-24-2017, 04:03 PM   #63
3 Rivet Member
 
chriscraw's Avatar
 
1991 35' Airstream 350
Austin , Texas
Join Date: Dec 2014
Posts: 238
I don't know who is still viewing this thread but I need advice. Recently replaced hydroboost and master cylinder on the 1991 350LE. Unfortunately before returning the old hydroboost for reman credit, I failed to remove the push-rod connecting the hydroboost to the master cylinder. By the time I realized my mistake, my return was shipped of to the remanufacturer. Not realizing that the push-rod length was critical, I was able to determine that the appropriate push-rod length for this set-up was 3.442" (GM part number 00377397, Bendix part number 129959)..both NLA. Found two replacements at the local wreckers (3.34" and 3.14"). Based on the GM length spec, installed the one measuring 3.34". Brakes worked great until used a few times..some time in "panic mode" to ensure all was well. Then things went wrong. The brakes started to lock-up (mostly front) until the newly rebuilt 454 could no longer move the MH! Smell of burning brake material and very hot disks particularly on the front. Waited for about an hour and, was able to drive home with normal very gentle braking.
Everything I read tells me the problem is that the push-rod I installed is too long and lot allowing the MC to bleed-off brake pressure. so, if that is the case, should I install the 3.14" version or am I chasing another problem. Help please!
__________________
chriscraw is offline   Reply With Quote
Old 03-24-2017, 05:20 PM   #64
Rivet Master
 
Boom Sounds's Avatar

 
1991 25' Airstream 250
Oxford , Oxfordshire
Join Date: Jun 2007
Posts: 707
Images: 5
Hi Chris,

Sounds like a right PITA. I had a quick scan (as I am sure you have) and can't see any for sale. Do you think it's possible that the rod was available as part of a kit? Something like this, although don't think this is the one:

http://www.oldsobsolete.com/products...-nos-14055058/

This thread might shed some light
http://www.4btswaps.com/forum/archiv...p/t-13890.html

Otherwise, try the guys on the Chevytruck forums. They might be able to turn up some leads.

The Light Truck Unit service and repair manuals for 1991 (I posted link in post 94 on the sticky) will tell more about the breakdown and fault finding for the master cylinder and hydro-boost, although you already look to have good information, so maybe not of help.

I do intend to replace the master cylinder and possibly the hydro-boost on my 1991 250, although that is unlikely to be for at least six weeks, possibly more. I can look at it all when I get it taken apart and get all the relevant part numbers/measurements, although appreciate that this is some way off. PM me if interested.

Good luck

Nick
__________________
Boom Sounds is offline   Reply With Quote
Old 03-24-2017, 08:07 PM   #65
3 Rivet Member

 
1986 34.5' Airstream 345
Alliance , Ohio
Join Date: Apr 2007
Posts: 177
Do you think it was possible you boiled your brake fluid during you test panic stops? If the fluid is old it probably contains some moisture. I had this happen to me in some rolling hills with my 345. Once it starts it seems to run away. Brakes dragging and generating more heat. I found myself giving it more gas until I realized something was wrong. Then it took both feet on the brake pedal and the emergency brake as well to bring it to a stop. White knuckles and smoking brakes all around. After cooling off for an hour, the trip home was fine. Needless to say I replaced all pads, calipers, fluid, and hydro boost that winter. But in hindsight I believe the fluid was the cause. Just some food for thought.
__________________
mehes is offline   Reply With Quote
Old 03-24-2017, 10:19 PM   #66
3 Rivet Member
 
chriscraw's Avatar
 
1991 35' Airstream 350
Austin , Texas
Join Date: Dec 2014
Posts: 238
All new components and fluid

Quote:
Originally Posted by mehes View Post
Do you think it was possible you boiled your brake fluid during you test panic stops? If the fluid is old it probably contains some moisture. I had this happen to me in some rolling hills with my 345. Once it starts it seems to run away. Brakes dragging and generating more heat. I found myself giving it more gas until I realized something was wrong. Then it took both feet on the brake pedal and the emergency brake as well to bring it to a stop. White knuckles and smoking brakes all around. After cooling off for an hour, the trip home was fine. Needless to say I replaced all pads, calipers, fluid, and hydro boost that winter. But in hindsight I believe the fluid was the cause. Just some food for thought.
Thanks for your suggestion however, the brake fluid was very fresh as was the hydroboost and master cylinder. We will be doing more testing this weekend to absolutely establish the cause of brake locking (also to closely inspect the caliper pistons in case). The reason for posting on this thread was to see if anyone had physically measured the length of the push-rod as some point so we could compare. Thanks again and glad your situation was resolved.
__________________
chriscraw is offline   Reply With Quote
Old 03-24-2017, 10:34 PM   #67
Dazed and Confused
 
Isuzusweet's Avatar
 
Currently Looking...
1983 31' Airstream310
Hillsburgh , Ontario
Join Date: Sep 2012
Posts: 2,433
I think you need to read this link. It explains a lot of how the hydroboost system can affect the brakes and the symptoms.

Part of the link provided.

5. If brakes are self applying and pedal is free, check for obstruction in the return line or a kinked connection between hydo-boost and pump reservoir. If obstruction or kink is found, go to step 6, otherwise go to step 7.

http://www.brakeandfrontend.com/oper...ssist-systems/

cheers
Tony
__________________
Per Mare, Per Terram and may all your campaigns be successful.

Its a recession when your neighbor loses his job; its a depression when you lose your own. "Harry S Truman"
Isuzusweet is offline   Reply With Quote
Old 03-24-2017, 10:34 PM   #68
3 Rivet Member
 
chriscraw's Avatar
 
1991 35' Airstream 350
Austin , Texas
Join Date: Dec 2014
Posts: 238
Thanks for response

Quote:
Originally Posted by Boom Sounds View Post
Hi Chris,

Sounds like a right PITA. I had a quick scan (as I am sure you have) and can't see any for sale. Do you think it's possible that the rod was available as part of a kit? Something like this, although don't think this is the one:

http://www.oldsobsolete.com/products...-nos-14055058/

This thread might shed some light
http://www.4btswaps.com/forum/archiv...p/t-13890.html

Otherwise, try the guys on the Chevytruck forums. They might be able to turn up some leads.

The Light Truck Unit service and repair manuals for 1991 (I posted link in post 94 on the sticky) will tell more about the breakdown and fault finding for the master cylinder and hydro-boost, although you already look to have good information, so maybe not of help.

I do intend to replace the master cylinder and possibly the hydro-boost on my 1991 250, although that is unlikely to be for at least six weeks, possibly more. I can look at it all when I get it taken apart and get all the relevant part numbers/measurements, although appreciate that this is some way off. PM me if interested.

Good luck

Nick
Nick..I already owed you a reply to your PM and will do so after "le crise".
The issue here seems to be that, although a standard exists for hydroboost length of push "rest and travel" of the piston, no standard exists for length of travel of the master cylinder and indeed the length of the mastger cylinder itself. This is the reason why standard parts were discontinued and the re-manufactured hydroboost carries the warning to remove the push-rod, spring, washer and retainer BEFORE returning the old hydroboost. Unfortunately, this instruction is "buried" in the box and other instructions which was my "undoing"
You are on the right track with your GM/Chevy forum comment as that is where I was able to determine the length the push-rod plays in brake performance (too short, no brakes, too long locks brakes). I have also found the procedure for measuring the correct depth of the push-rod to ensure adequate return of the master cylinder piston which is what we will be doing next week when I remove the master cylinder for the second time. My reason for posting this issue is in the hope that (before you carry-out your refurbish) someone can confirm the correct push-rod length which I think is 3.14"
In any event, make sure you retain your old hydrobooster and bits until you install and check mc interface and operation.
I'll let you know what happens. Thanks Nick for your input.
__________________
chriscraw is offline   Reply With Quote
Old 03-24-2017, 10:51 PM   #69
3 Rivet Member
 
chriscraw's Avatar
 
1991 35' Airstream 350
Austin , Texas
Join Date: Dec 2014
Posts: 238
Disappointment with article

Quote:
Originally Posted by Isuzusweet View Post
I think you need to read this link. It explains a lot of how the hydroboost system can affect the brakes and the symptoms.

Part of the link provided.

5. If brakes are self applying and pedal is free, check for obstruction in the return line or a kinked connection between hydo-boost and pump reservoir. If obstruction or kink is found, go to step 6, otherwise go to step 7.

http://www.brakeandfrontend.com/oper...ssist-systems/

cheers
Tony
Tony my friend..thanks for the above link however, I had already found this and thought it might be useful. But..although below figure 11, the author indicates dealing with 4 problems (noise, pedal return, over sensitive braking and self-applying brakes), there is no specific reference to the self-applying brakes and in particular the relationship of the push-rod length being related to "self-applying brakes". Great article if one is having problems with hydroboost operation but mine is working fine..the push-rod extends on brake pedal operation and retracts when the pedal is released. The problem I'm having is determining the return travel of the push-rod that allows the master cylinder piston to release brake pressure after the pedal is released...thnaks again..will keep al informed of any solution that we find!
__________________
chriscraw is offline   Reply With Quote
Old 03-24-2017, 11:37 PM   #70
3 Rivet Member
 
1983 31' Airstream310
Santa Cruz , California
Join Date: Sep 2008
Posts: 157
Images: 12
Having been through a lot of this exact grief with my 310, I can tell you that yes, the rod length is critical, and you can put a shim between the MC and hydroboost to correct for it. It also varies from unit to unit, so be very cautious about some magic dimension that might or might not apply to your unit.

In my case, the lockup problem was mostly the result of very fine rust particles collecting in the MC. When applying the brakes, that pressure was enough to actuate the calipers. The spring in the calipers (which also get rusty and drag) was not enough to push back through those orifices to get the fluid back into the MC. Is the fluid in the MC clear or rusty?
__________________

__________________
dljosephson is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Grabbing Brakes 74Tradewind Brakes & Brake Controllers 15 08-05-2004 06:26 PM
Intermittant Brakes dinoburb Brakes & Brake Controllers 4 11-12-2003 09:00 AM
Tag Axle Brakes cooperhawk General Motorhome Topics 1 06-23-2003 01:48 PM
Trailer brakes won't lock-up? John Brakes & Brake Controllers 24 02-06-2003 01:22 PM
Heeeelp! My brakes have failed...anyone have a similar experience? williamhenshall Airstream Motorhome Forums 9 07-12-2002 04:04 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:34 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.