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Discussion Starter · #1 ·
Trouble shooting my brake boost problem on my '93 D-250 by verifying pump produced 25 " vacuum, I broke the plastic nipple off the low vacuum switch . Finding out it's unobtanium, and besides brake warning light and water in fuel light staying on, I lost the movement on power windows . What's the substitute that others have engineered ? I don't see any tie in to window regulators, but the switch may complete a circuit . HELP Dan Renovetz
 

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That part seems to have been in short supply for quite a while.
From Google and various forums, i got a listing on a dealer in Rochester NY, and when I called the phone # -talked to a parts lady, she said Chrysler took it out of their system in 2014 . I only hope I can get one from somebody who is parting out a 1st gen for the engine . Working on that potential now .
 

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Discussion Starter · #6 ·
From Google and various forums, i got a listing on a dealer in Rochester NY, and when I called the phone # -talked to a parts lady, she said Chrysler took it out of their system in 2014 . I only hope I can get one from somebody who is parting out a 1st gen for the engine . Working on that potential now .
Took my part to our local ATHS club meeting Sunday. A member took a picture and posted it on a F-book forum/ page . I had 2 offers of take off parts on Tuesday and confirmed one to be shipped out of Iowa. . Brake boost is still questionable, as it sometimes works- most times not .
 

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Older car parts can be a challenge. I guess manufacturers don't think about trucks that seem to go on forever. Lots of parts get reproduced but electrical sensors are often the last thing to go that route. Curious, which style vacuum pump do you have. The early models had twin diaphragm vacuum pumps which was changed to a single vane type pump. Those early pumps had a bad reputation for failure. '93 would have been a borderline year for the changeover.
 

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Discussion Starter · #8 ·
Older car parts can be a challenge. I guess manufacturers don't think about trucks that seem to go on forever. Lots of parts get reproduced but electrical sensors are often the last thing to go that route. Curious, which style vacuum pump do you have. The early models had twin diaphragm vacuum pumps which was changed to a single vane type pump. Those early pumps had a bad reputation for failure. '93 would have been a borderline year for the changeover.
Mine has the vane pump..............typical to General Motors applications . But I'll be reconsidering a hydroboost changeover . Took my wife to chiropractor this AM and find it strange that sometimes I get brake boost, but most times not . From comments on various forums, apparently a double diaphragm boost chamber can do that .
 

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If you have the vane pump then yours would have the 3 section pump. Later models changed to a 2 section pump. Earlier models had the twin diaphragm pumps . The later pumps are rebuildable and the kits aren't all that expensive. A company here in NC, Gould Gear and Electric, has the best kits. You might also check for a vacuum leak. As hoses age they sometimes crack. Wouldn't hurt to add a vacuum gauge to the dash. Of course your vacuum booster on the brakes could be failing also. Changing to hydroboost wouldn't be difficult. You can leave the vacuum pump section in place and just change out the power steering pump unit. Then you'd need the hydroboost set from a Dodge Cummins. Here's a video from Gould showing the rebuild process.
This is for the 2 section pump.
 
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