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General Information => Troubleshooting => Topic started by: rabbitman on December 26, 2008, 02:54:07 pm

Title: Vacuum pump woes.
Post by: rabbitman on December 26, 2008, 02:54:07 pm

Ok, how long is the vacuum pump diaphram supposed to last?

I replaced mine in march 2007 for no reason, I thought maybe my brakes would work better. :roll: Then in February 2008 it ripped so I changed it again, now it's ripped again. :x  So I get 10-11 months per diaphram.
Yeah yeah, I know I need a rotary pump, I saw one on ebay about a week ago and didn't feel like spending 25 bucks on one. :x So I bought two rebuild kits on ebay for um...25 bucks :roll:
Anyways I don't know if I'm doing something wrong or what, I follow the manual but maybe I'm still missing something. Thanks

Title: Vacuum pump woes.
Post by: rabbitman on December 28, 2008, 02:47:23 pm

Does anybody else have to do yearly diaphram replacements?

Title: Vacuum pump woes.
Post by: jtanguay on December 30, 2008, 05:48:19 pm

what does the tear area look like? can you take pics? might give hints as to whats happening... maybe the diaphrams your buying are low quality?

Title: Vacuum pump woes.
Post by: rabbitman on December 30, 2008, 06:20:26 pm

I'll take a pic when I change it after the new one comes.

Title: Vacuum pump woes.
Post by: Rabbit TD on December 31, 2008, 10:34:11 pm

Quote from: "rabbitman"

Does anybody else have to do yearly diaphram replacements?

I've had 3 diesel rabbits over the years, 2-80's and this 81 and believe it or not I never had one of the diaphram ones fail, I'm pretty sure the one on the car now has been replaced before but when I don't know and I've put close to 35000 on it the last 3 years.  I have the rotory one on the engine I'm putting together now.  The 80 Rabbits I had were back in the early 90's.  My son messed them both up, I just got back into the little diesels recently.

Title: Vacuum pump woes.
Post by: rabbitman on January 02, 2009, 11:39:03 am

I put one of my new diaphrams outside at -45F and it got rock hard, so I figured that could be a contributing factor. When the car is plugged in or running I'm sure there's enough heat getting to the pump to soften the rubber but it probably still weakens it.

Title: Vacuum pump woes.
Post by: rabbitman on February 25, 2009, 04:21:08 pm

Well I've been on vacation since January 5 so I'm finally fixing the pump.....and brake hose.....and brake line that I ruined taking the hose off, it never ends.
Here are the pics.
(http://i249.photobucket.com/albums/gg218/rabbitdude82/Rabbit030.jpg)
You can see the middle of the diaphram is ripped out.
(http://i249.photobucket.com/albums/gg218/rabbitdude82/Rabbit033.jpg)
This is the same brand as the one I ripped.

Title: Vacuum pump woes.
Post by: fatmobile on February 25, 2009, 10:20:03 pm

Yep, pre-stress the diaphram before you tighten it down.
 Otherwise it stretches it hard every pulse.

Title: Vacuum pump woes.
Post by: rabbitman on February 27, 2009, 12:13:31 pm

According to the Bentley your supposed to make sure it's relaxed when you tighten it. I guess it makes sense to pre-stress it though so it doesn't have to stretch so much. Thanks