Shaky T-Bird

Maintenance/Repairs
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1

I have a 1986 Ford Thunderbird that is running rough. I can feel the brakes vibrating when at a complete stop and the car runs rough like it has a vacume leak somewhere but I can’t find it.

The master brake cylnder and brake booster were both replaced which should have fixed the problem, but has not. Any advice?

The car has 253,000 miles on it and my wife is the original owner.

2

Its always best to start with the basics - plugs, wires, fuel/air filters.

Feeling vibration in the brakes at a stop is very weird. Can you describe that better.

How did you look for a vacuum leak? I like to use an unlit propane torch with a piece of hose attached - fish it all around vacuum connections & intake area. The engine will rev up a bit of you find it.

3

Thanks for the tip on checking for leaks.
The vibration is felt through the brake pedal. Kind of a thumping.
I have found a vacuum hose that is broken off of a valve that sits on top of the engine facing the brake booster.
I am now trying to find out what the valve is called to get a replacement.

4

That broken vacuum connection may be the PCV Valve. Here’s a picture of it at autozone.com. To see the image, you’ll need to register at the site, and come back here and click on this link: http://www.autozone.com/autozone/catalog/parts/partsShelf.jsp?categoryDisplayName=Routine+Maintenance&fromType=parts&fromString=search&parentId=42-0&currentPage=1&filterByKeyWord=pcv+valve&isSearchByPartNumber=false&navValue=14200541&categoryNValue=14299999&fromWhere=&itemId=541-0&displayName=PCV+Valve&searchText=pcv+valve

5

I checked, the piece that the vacuum line attaches to isn’t the pcv valve. The pcv valve is on the passenger side of the engine. This item is on the drivers side. The chilton manual had a line drawing of what they called the diaphragm assembly for the carburator. This thing looks like that, but is not built into the carb.
It attaches with two screws to the top of the engine and looks as if there is a piece that goes down into the engine block that controls it.
Tomorrow I will take a picture of the thing and attach it as a file to this post. Then maybe you can help me identify it. Thanks.

6

Here is a picture of the piece that is broken. Any help in identifying it would be helpful.