Author Topic: Vacuum pump woes. (Read 4568 times)

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

rabbitman · « **Reply #1 on:** December 28, 2008, 02:47:23 pm »

Does anybody else have to do yearly diaphram replacements?

jtanguay · « **Reply #2 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?

rabbitman · « **Reply #3 on:** December 30, 2008, 06:20:26 pm »

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

Rabbit TD · « **Reply #4 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.

rabbitman · « **Reply #5 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.

rabbitman · « **Reply #6 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.

You can see the middle of the diaphram is ripped out.

This is the same brand as the one I ripped.

fatmobile · « **Reply #7 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.

rabbitman · « **Reply #8 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