Reply
 
Thread Tools Display Modes
 
Old 06-03-2018, 02:13 PM   #1
Member
 
Wire89's Avatar
 
Join Date: Jul 2017
Location: Santa Barbara
Posts: 52
Brakes & Vacuum Troubleshooting

Back with another one...starting to seem like one thing gets fixed and another raises it's head. This time the brake peddle occasionally goes hard, other times it's a typical gentle push. On three occassions the front brake pads maintained contact with the rotors and began to heat up. This has been going on for approx. 3 months. The vacuum pump was replaced about 4 months ago when it went out on me along CA's 166. Pump still draws good vacuum and holds at 26 inches for a good long time. The brake system was also completely bled, including the ABS, and all calipers checked about two months ago.

Yesterday, I performed the simple brake booster check...pumping brakes with engine off to a hard state, then starting engine with slight pressure on pedal to see if descends under vacuum. That worked out fine. I then started a vacuum diagnosis on all vacuum connections and narrowed it down to a fairly rapid leak in the AC line. However, though leaking fast when I shut it down, it still pulled about 25 inches, a bouncy unstable 25 inches. The last easily accessible AC line connection (just behind the battery and above the heater core) holds vacuum, and the first easily accessible connection inside the cab does not hold vacuum. In fact it barely pulls 15 inches. So in reading other posts it sounds like a check valve or reservoir leak, which I've also read is an absolute PITA to access.

So, before I make the AC leak attempt, in the interest of resolving the brake problem first, can I safely plug the AC vacuum port on the vacuum manifold tree and run the vehicle to see if the brake problem is still present? I know a low vacuum will make the pedal hard to push, but is it reasonable that a low or unstable vacuum can also cause the pads to not fully disengage at times? Should I be looking elsewhere before tackling the AC leak?

thanks in advance.
__________________

__________________
2002 E350 7.3L
Wire89 is offline   Reply With Quote
Old 06-10-2018, 05:34 PM   #2
Member
 
Wire89's Avatar
 
Join Date: Jul 2017
Location: Santa Barbara
Posts: 52
So I ended up plugging the vacuum line for the AC and made my way down to Agile this weekend (another pleased RIP customer), 180 miles+ each way. On the way down, late night no traffic, the brakes were very consistent. On the way back, daytime lots of traffic, the brakes would slowly tighten up in the lower speed frequent use traffic situations, then return to normal after increased speed and/or no use. However, they were much better than previous, and they didnít seem to keep contact and heat up. So Iím back to wondering if I should look further at booster or master cylinder? Maybe this isnít so out of ordinary?

Any feedback appreciated.
__________________

__________________
2002 E350 7.3L
Wire89 is offline   Reply With Quote
Old 06-10-2018, 07:36 PM   #3
Senior Member
 
Bbasso's Avatar
 
Join Date: Jan 2012
Location: Western North Carolina
Posts: 1,223
Vacuum pump might be taking a dump, rather easy and affordable for DIY.
__________________
Rob.
Current:
2001 E350 PSD w/ a bunch of stuff.
And had three other E350s...
Bbasso is offline   Reply With Quote
Old 07-10-2018, 10:40 PM   #4
Senior Member
 
Join Date: Nov 2014
Location: Aurora, CO
Posts: 298
Just had my vacuum pump go. I have no idea how many miles mine had on it, but if anyone out three hasn't changed theirs in a while, or has a new to them diesel van, it may be worth swapping it out. When it goes, you have no power brakes and there is NO backup system other than stepping on the brake pedal hard, and even then I doubt my van would stop coming down a mountain pass!

As Bbasso said it is a pretty easy fix that can be done in the field with a few tools(10mm wrench, serp belt tool, pliers), as long as you have a spare pump, or can get to an auto parts store to get one.

Just thought I would toss that out there as a PSA!
__________________
New Van: 2000 Ford E350 SMB RB42
Old Van(sold): 1995 Dodge B3500 SMB RB33
Ben10281 is offline   Reply With Quote
Old 07-11-2018, 07:03 AM   #5
JWA
Senior Member
 
Join Date: Jan 2011
Location: Reynoldsburg, Ohio
Posts: 1,840
Send a message via Yahoo to JWA
Quote:
Originally Posted by Ben10281 View Post
As Bbasso said it is a pretty easy fix that can be done in the field with a few tools(10mm wrench, serp belt tool, pliers), as long as you have a spare pump, or can get to an auto parts store to get one.

Just thought I would toss that out there as a PSA!
Good advice and I'll add all of us should carry a spare serpentine belt regardless of fuel---neighbor just recently blew one in his F-Series diesel that cost in excess of $600 to replace out on the road---not counting his down time.

The all time best too (IMHO) is this one: http://www.gearwrench.com/gearwrench...-tool-set.html Affordable, convenient to stow out of the way until needed and very usable on most every vehicle out there.

HTH
JWA is online now   Reply With Quote
Reply

Thread Tools
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

Powered by vBadvanced CMPS v3.2.3
Disclaimer:

This website is not affiliated with or endorsed by Sportsmobile SIP or any of its affiliates. This is an independent, unofficial site.


All times are GMT -6. The time now is 06:14 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2018, vBulletin Solutions, Inc.