Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - A couple problems - TH400 trans and power brakes
View Single Post
  #3 (permalink)  
Old 03-15-2010, 06:32 PM
cobalt327's Avatar
cobalt327 cobalt327 is offline
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Posts: 5,031
Wiki Edits: 1616

Thanks: 128
Thanked 616 Times in 565 Posts
Originally Posted by Torque454
If the booster is leaking too much would that cause my trans shifting problem?
Could- if the modulator is plumbed off of a "T" shared w/the booster. Possibly even by the booster leaking vacuum enough to lower the vacuum at the port where the modulator is supplied from, but it would have to be leaking very bad- and this would make the engine run terrible, if at all- at idle, especially.

Disconnect the booster and plug the hose to see if that cures the stumble. Just remember the brakes will not be up to par. So be careful, and only do this in a safe area. But I'm betting the booster is toast and needs replaced in any event.

It could be a bad governor gear, as well. Bad gear = no shift out of first.

If it's a bad modulator, or the hose to the modulator is split or off, there will still be a shift w/enough RPM. IIRC, there will not be any shift at any RPM w/a worn out gov. gear.
Reply With Quote