Recently I have noticed the idle speed increases by 100-200 rpm when I release the brake pedal after waiting at a stop light in neutral. The car is a 4 speed manual. Is this normal, or does it indicate perhaps a vacuum leak or some other problem?

Steve Hamilton
1969 280SL
Vancouver, BC

Maybe a vacuum leak in the booster?

Thanks for your help.

I removed the brake booster vacuum hose from the intake manifold, and plugged the hole with a rubber ball. The brakes no longer affect the idle speed.

Does this mean I need a new brake booster? Is there another test I should do to confirm the booster is at fault? Are booster rebuild kits available for the 280SL?

Steve

Someone else may follow-up with a suggestion. But I see no other tests to perform: you need a brake booster. This could be rather expensive, so I suggest you make plenty of calls and shop for a price. And someone may have a rebuild kit, though I don't know of one myself.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1837232062&sspagename=ADME:B:SS:US:1

Seller has a feedback rating of zero.

Thanks for the link. It looks a bit dicey considering the cosmetics and 0 feedback... I may have to spring for a new one.

Steve

There are places in Hemmings that will rebuild brake boosters quite reasonably. It takes a week or so. I used one when I had a Porsche 928 and saved a bundle.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

You might try White Post Restorations, White Post, VA. 540-837-1140 or www.whitepost.com