Home » Public Forums » GMCnet » Disappointing Weekend - Air in brake lines
| Disappointing Weekend - Air in brake lines [message #141482] |
Mon, 29 August 2011 07:48  |
 |
Michael Leipold
Messages: 318
Registered: April 2011
Location: Greensboro NC
Karma: 2
|
Senior Member |
|
|
I can not get the air out of my brake lines.
So I am planning on driving from NC to CA Wednesday and the only thing I have left to really do is bleed the brakes.
I put a new master cylinder on it and have no issues with the fronts, but the rears just keep blowing bubbles.
I have installed speed bleeders into the wheel cylinders, but every time I think I have all the air out, more comes out.
Things I did get done this weekend:
New KYB shocks all around, the old ones were labelled Delco and had zero rebound.
Replaced the carpeting with tiled paneling from the entry door to the top of the steps. Added insulation underneath.
Installed a Firestone air compressor and 15L air tank.
Installed Xantrex Inverter/Converter and additional breaker box.
Installed an electronic safe in one of the cabinets.
Things I did since purchasing:
Repaired leaky fresh water tank.
Replaced both mufflers with Dynomax Super Turbos.
Installed engine compartment side vents.
Built battery tray for drivers side.
Built larger battery tray for passenger side.
Moved house batteries to drivers side.
Replaced upper seal in steering gear box.
Installed air suspension seats.
Patched holes in roof.
Replaced external transmission cooler and added external filter.
Relocated external fuel filter closer to tanks (was up front).
Installed H4 Headlight Assemblies and Sylvania Silverstar Ultra Bulbs.
Installed fresh air vent for driver. (Thanks JR)
I probably did more, just can not remember it at the moment.
So for the brakes, I did not use a tool on the proportioning valve, could that be my issue?
Or could I have a bad master cylinder?
1973 GMC 26' Glacier - Unknown Mileage - Has a new switch pitch transmission with Powerdrive 
[Updated on: Mon, 29 August 2011 08:13] Report message to a moderator |
|
|
|
| Re: Disappointing Weekend [message #141485 is a reply to message #141482] |
Mon, 29 August 2011 08:07  |
kingd
Messages: 592
Registered: June 2004
Karma: 2
|
Senior Member |
|
|
I found when using even BRAND NEW speed bleeders, air was getting sucked passed the threads back into the system when the bleeders were loosened to allow bleeding. Going to regular bleeders and 2 person bleeding fixed problem. 2 person bleeding can also be used with the speed bleeders using the closed, down, open, closed, up process. Remember its a long way from the Master Cylinder to the rear wheels cylinders on a GMCMH. A power bleeder has been the solution for lots of people.
DAVE KING
DAVE KING
lurker, wannabe
Toronto, Ontario, Canada
|
|
|
|
|
|
|
|
|
|
| Re: Disappointing Weekend - Air in brake lines [message #141520 is a reply to message #141482] |
Mon, 29 August 2011 11:19 |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
|
Senior Member |
|
|
from lots of forum reading. Brake bleeding problems are solved by 3 methods:
1. pressure bleeder(jim hupys or equivalent). I bought a motive one, because I was going to use it on other vehicles. but I would buy Jim's if I had a do-over. you fight sealing the plate on others.
2. proportioning valve needs replaced with brass ones(pressing button on valve solves nothing).
3. rare- master cylinder is bad, or hoses are bad.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
|
|
|
|
|
|
|
|
| Re: Disappointing Weekend - Air in brake lines [message #141537 is a reply to message #141482] |
Mon, 29 August 2011 12:52 |
A Hamilto
Messages: 4508
Registered: April 2011
Karma: 39
|
Senior Member |
|
|
| lilmyk wrote on Mon, 29 August 2011 07:48 |
I can not get the air out of my brake lines.
...
I have installed speed bleeders into the wheel cylinders, but every time I think I have all the air out, more comes out....
So for the brakes, I did not use a tool on the proportioning valve, could that be my issue?
Or could I have a bad master cylinder?
|
Check the connection where the rear brake line connects to the MC. IF THE MC IS GOOD, and those "speed bleeders" are ok (I don't even know what they are), the only possibility is a leak in the line somewhere. And the most likely place(s) for a leak in the line is where you have changed something. If you are getting air from both rear wheels, the leak is either BOTH speed bleeders, or somewhere between the MC and the proportinoning valve. If a line hasn't spontaneously sprung a leak, that leaves connections you have worked on. That points you at the connection at the MC, or the speed bleeders.
|
|
|
|
|
|
|
|
|
|
| Re: Disappointing Weekend - Air in brake lines [message #141573 is a reply to message #141482] |
Mon, 29 August 2011 17:09 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
|
Senior Member |
|
|
i have not tried on my gmc yet, but my old porsche which had the proportioning valve was a big pain to bleed,
get at bulp pump like you would see inline from gas tank to outboard motor. hook at bleeder and pump to pull vacuum. .
worked on the porsche, i would expect it to work on this too.
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
|
|
|
|
| Re: [GMCnet] Disappointing Weekend [message #141575 is a reply to message #141533] |
Mon, 29 August 2011 17:16 |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Gene,
No GMC experience but on other vehicles it sure does take some time!
RANT ON!
I am on a crusade to get GMC owners to flush their brake fluid regularly.
Last May at Bean Station I asked people if they flushed their brake systems regularly and got almost no positive responses.
While I have no evidence in hand I'll bet dollars to donuts a significant number of failed master cylinders, wheel cylinders, brake
calipers, etc. are caused by water in the fluid rusting the bores which in turn tears up the seals and causes leaks.
The first year Helen and I toured the USA in Double Trouble the master cylinder in Double Trouble failed. It has a P-30 type M/C and
when I checked to see what the problem was I noted fluid running down the front of the booster indicating that the "rear" seal had
failed. We wound up changing it in a motel parking lot and bleeding it was no fun!
For a one time expenditure of $75 plus shipping GMC owners can buy one of Jim's pressure bleeders and it makes a job that is a PITA
simple!
Sure you can buy a cheapie pressure bleeder for $60 or so on eBay but I'll bet you'll have problems with the plastic cover leaking.
The thick aluminum plate that Jim uses DOES not flex and allow fluid to leak out at the top of the master cylinder when bleeding the
brakes. Plus it fits both the GMC OEM M/C and the P-30 M/C.
I find it fascinating that guys will spend thousands of dollars to upgrade to disk brakes, reaction arm systems etc but hesitate to
spend $75 to maintain that expenditure!
RANT OFF!
Regards,
Rob
-----Original Message-----
From: gene Fisher
I have always had good luck with gravity bleed with the GMC.
takes a while, but gets rid of the air
gene
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: Disappointing Weekend - Air in brake lines [message #141582 is a reply to message #141482] |
Mon, 29 August 2011 17:46 |
fred v
Messages: 999
Registered: April 2006
Location: pensacola, fl.
Karma: 0
|
Senior Member |
|
|
| lilmyk wrote on Mon, 29 August 2011 07:48 |
I can not get the air out of my brake lines.
So I am planning on driving from NC to CA Wednesday and the only thing I have left to really do is bleed the brakes.
I put a new master cylinder on it and have no issues with the fronts, but the rears just keep blowing bubbles.
I have installed speed bleeders into the wheel cylinders, but every time I think I have all the air out, more comes out.
|
i had the same problem even using a pressure bleeder. mine was the right side center wheel that kept showing bubbles. never could get a solid flow. i finally figured air was entering at the bleed valve somehow.
i believe the main problem is at the proportioning valve where the tubes form an upward loop. a big bubble can collect there an it requires fast flow to push it out.
my brakes never felt great until i replaced the MC. it crapped out again and after installing and bleeding again i finally got all the air out and have great brakes now.
stay after it and you will finally succeed.
Fred V
'77 Royale RB 455
P'cola, Fl
|
|
|
|
|
|
| Re: [GMCnet] Disappointing Weekend [message #141594 is a reply to message #141583] |
Mon, 29 August 2011 19:05 |
|
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
|
Senior Member |
|
|
Gene,
Well now there's TWO of us on this crusade!
ATE is a bit more expensive than the Ford High Temp and I think the ATE specs are a bit better but it really doesn't make that much
difference.
The nice about the ATE fluid is the two different colors because you can tell the instant the old fluid is out as the color changes.
IIRC Larry Weidner told me about the ATE fluid.
Regards,
Rob M.
-----Original Message-----
From: gene Fisher
A concept I have been pushing for 10 years
here
http://gmcmotorhome.info/brakes.html#press
and here
http://www.my-gmc.com/Speedi-Bleed-right-view.jpg
and here
http://gmcwsproducts.blogspot.com/2011/03/amazing-new-gmc-vendor-products.html
and
I even bought one from Jim,
http://gmcwsproducts.blogspot.com/2011/03/amazing-new-gmc-vendor-products.html
and
I have 2 GMCs with 6 wheel disk brakes , new master cyls, and
hydraulic brake locks,
and
I flush them every 2 years with gravity bleed and it costs me $10.00
for Ford High Temp.
as you say, the problem is not the bleeding
it is the bleeders !!!!
;>)
gene
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
| Re: [GMCnet] Disappointing Weekend [message #141646 is a reply to message #141575] |
Tue, 30 August 2011 06:56 |
jhbridges
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
|
Senior Member |
|
|
The ABS on my first Town & Country died at 140K miles. Fortunately, since it was the first year of manufacture, Chrysler warrented the entire system for 100K miles, and the compressor and 'Hydraulic Control Assembly' - read master cylinder - for the life of the van, owner not important. So, cost me $300 and Chrysler $2800 to heal it. The tech told me, the ABS stuff dies on dirty or especially waterlogged fluid. Since then, I flush the brakes every two to three years, when I do belts, hoses, and coolant. Only thing I've done to any of my rides' brakes since is shoes/pads.
--johnny
--- On Mon, 8/29/11, Rob Mueller <robmueller@iinet.net.au> wrote:
From: Rob Mueller <robmueller@iinet.net.au>
Subject: Re: [GMCnet] Disappointing Weekend
To: gmclist@temp.gmcnet.org
Date: Monday, August 29, 2011, 10:16 PM
Gene,
No GMC experience but on other vehicles it sure does take some time!
RANT ON!
I am on a crusade to get GMC owners to flush their brake fluid regularly.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons.
Braselton, Ga.
I forgive them all, save those who hurt the dogs. They must answer to me in hell
|
|
|
|
| Re: Disappointing Weekend - Air in brake lines [message #141650 is a reply to message #141482] |
Tue, 30 August 2011 07:13 |
|
Michael Leipold
Messages: 318
Registered: April 2011
Location: Greensboro NC
Karma: 2
|
Senior Member |
|
|
Ok, Ok, I will get a pressurized bleeder, I understand the benefits, I just did not have the time this go around.
I replaced the master cylinder last night, I went to NAPA, they have a new part number for the MC. It is a 1 1/4 bore.
Anyways, fronts, I love the fronts, no air at all.
Rears, well, they appear to be air free. With the engine off, the brakes are hard as rocks, with it running, the vacuum assist, in my opinion assists too much, but it feels the same as it did before I changed everything. Maybe I should have just left the old one on. I have not driven it yet, freak thunderstorm hit before I was able to get the front tires back on. I might go home at lunch and put them on and drive it back to work.
I read somewhere that it takes a few miles for the brakes to "feel" right, so here's to hoping.
As of right now, I am planning on heading to Cali tomorrow to get married next weekend. I will keep you all updated.
PS.. I filled 100 4oz mini mason jars with moonshine last night and my fiancee labeled them, we are giving them out as our wedding favors.
1973 GMC 26' Glacier - Unknown Mileage - Has a new switch pitch transmission with Powerdrive
|
|
|
|
|
|
Goto Forum:
Current Time: Sat Feb 01 04:03:48 CST 2025
Total time taken to generate the page: 0.02292 seconds
|
GMCforum
Search
Help
Register
Login
Home
