Date: Thu, 26 Mar 2009 14:00:16 -0700
Reply-To: dylan friedman <insyncro@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: dylan friedman <insyncro@YAHOO.COM>
Subject: Re: Pulsating Brake Pedal (Need Solution)
In-Reply-To: <f038a2e20903261342l118ae8a0x986012ce37cecc33@mail.gmail.com>
Content-Type: text/plain; charset=iso-8859-1
You have narrowed it down to the wheel.
Pull the brake assembly and see what it looks like.
Sometimes a piece of the pad fuses to the drum and creates an uneven surface and you feel it in the pedal.
This happens usually after a long drive in the rain and you come home and apply the emergency brake.
It will make a pop when you release the brake.
You drive off and it seems ok, but it pulsates.
This has been my experience.
Clean the brake surface and see how it goes.
dylan
________________________________
From: Blake Heinlein <blakeheinlein@GMAIL.COM>
To: vanagon@GERRY.VANAGON.COM
Sent: Thursday, March 26, 2009 4:42:26 PM
Subject: Pulsating Brake Pedal (Need Solution)
Hi everyone, so here's my situation.
My 1984 Westy has a pulsating brake pedal and undulating slowing during
braking. I can actually see my leg move up and down while braking. I need
help troubleshooting my problem.
I have been able to isolate the culprit it to the back right wheel. How do I
know this? If I clamp off the rubber brake line to the right rear wheel, the
brake pedal is perfectly smooth and the stop is smooth. That means that 3 of
the brakes are working perfectly.
Here is the work I have done and in order that is was completed. I always
did the work to both sides of the van at the same time.
1. Replaced rear brake shoes about 1-1/2 years ago (Did not turn the rear
drums at this time)
2. Had a local repair shop replace the rear wheel bearings about 1 year
ago (This is the only work I hired out)
3. Bleed brake system and flushed with new fluid (The rest of the work
was done in the last 2 months.
4. Installed new rear drums and the pulsation was worse so I returned
them.
5. Turned the original rear drums and installed them
6. Installed new front wheel rotors and brake pads
7. Greased and adjusted the front wheel bearings
Symptoms and/or current conditions of van:
1. There are no wheel vibrations while driving the van
2. None of the brakes drag when the brake pedal is up (brakes off)
3. The parking brake engages the rear brakes at 4 clicks. There is free
play in the parking brake linkage when they are released.
4. The brake pedal feel is firm and high and does not leak down. The best
I've had since I've owned the van.
5. The van stops quickly
6. The drum brakes are adjusted so they just slide on and then I backed
the ratchet off by 3-4 clicks.
7. None of the 4 brake cylinders leak
8. I have checked that all the rear brake shoe linkage is properly
assembled.
9. The drum brake positioning bolts are installed.
10. The drum brakes are free of dirt and grease at installation. Lightly
sanded pads to removing any glazing
Here are some of my thoughts about what might be wrong:
1. Axle is bent
2. Hub (part with the wheel studs) is bent
3. Something wrong with wheel bearings
4. Something wrong with proportioning valve to rear wheel
5. The axle nut is not torqued correctly
6. Brake pads don't seat properly in the drums (i.e. the
curvature radius is different)
So these are all my thoughts. Now it's your turn to help solve the puzzle.
Thanks in advance to everyone.
Blake HeinleinSacramento, CA
http://blakeheinlein.googlepages.com/
| 
