'81 633 Pneumatic Brake Booster Replacement

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martinmeba
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'81 633 Pneumatic Brake Booster Replacement

Post by martinmeba »

I have an 01/81 633 with a pneumatic brake booster. I looked through the history and see a lot of insight into the later hydraulic boosters but need help with this earlier model. I had my brake pedal go to the floor while coming home the other day which I chased down to the master cylinder. I have a replacement part in hand. I then was advised that I should check my booster to see how it is doing. Upon testing it, it appears to be leaking.

This is the booster:
http://www.realoem.com/bmw/enUS/part?id ... 4331112520

As you can see, it is no longer available. It seems that my options are to have this one rebuilt or to source another. Is there a replacement part that I could substitute? Is it worth rebuilding? I am trying to figure out my options here and any thoughts would be appreciated.
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by ron »

LOCATION in your profile please.
They are ALWAYS rustier than you thought!!!!!!
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martinmeba
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by martinmeba »

To reply to my initial post, this is the ATe part number:
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martinmeba
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by martinmeba »

OK. I just answered my own question.

I spoke with an Ate wholesaler. I had tried to source the part from BavAuto and they told me it is not available. The wholesaler said that is not true and it is definitely available. The wholesaler also recommended rebuilding it instead of replacing it so I am going to explore that option now. Anybody know a good place to send them out for rebuild?

Martin.
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by bpoliakoff »

Scroll down from your post and you will see a post from JCS.. and if not search for him on the forum He is a wizard at rebuilding the booster etc. Probably the best way to go
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JCS
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by JCS »

bpoliakoff wrote:Scroll down from your post and you will see a post from JCS.. and if not search for him on the forum He is a wizard at rebuilding the booster etc. Probably the best way to go
Thanks Bert,

But this is a vacuum booster, and I only rebuild Hydraulic Brake Servo Boosters.

Here is a link to Husker BMW, they show it as available, it could be NLA, call first.
https://www.bmwdirectparts.com/oem-part ... 4331112520

Best,
Jay
'88 M6, Red/Tan
My NEW Website https://www.jaysbmwparts.com/
martinmeba
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by martinmeba »

Thanks JCS - I would have contacted you but everything seemed to point to you specializing in the hydraulic boosters only. Thanks for the link and I will check them out. The Ate rep I spoke to recommended rebuilding - there is a 4-5x price differential.

martin.
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by bpoliakoff »

Look in Hemmings Motor News in the services offered section. There are several guys who rebuild vacuum boosters. One that comes to mind is a guy who calls himself "Booster Dewey" I do know he has been around forever. I just googled him and he does have a website and legitimate business in Portland
81 Euro 635 M90 with motronic. Currently under a complete nut and bolt restoration. Pictures at
flickr.com/photos/bertsphotos.
martinmeba
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by martinmeba »

So - belated followup to the above.

Thank you bpoliakoff - Booster Dewey could not help me - he seems to specialize in muscle cars and then jags and ferraris. He did refer me to a place in Pittsburgh - Power Brake X-Change - http://www.powerbrakex-change.com/. They had good follow-up and quoted a 10 day turn and they were done in about 5. It looks like they rebuild a variety of things so FYI.

I got it back yesterday and got it in this afternoon. Now to put everything else back together. The up side was that the fuel lines were looking bad but I was putting off doing them. While staring in the hood last weekend, I realized that with the booster and master cylinder out of the way the hardline/softline connection in the hood was right in front of me so I changed those out. Next I will put in the new master cylinder, then new brakelines, then bleed the whole thing out. May not get all of that done tomorrow but I think I will at least have everything in the hood done.

martin.
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Re: '81 633 Pneumatic Brake Booster Replacement

Post by jdooth »

just replaced my early sharks massive dual diaphragm with the small e28/e30 unit, bolted right up.
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