Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic -- Hot Rod Forum

Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Transmission - Rearend> Chevy 350cu with th350 transmission not shifting after installing new vacum hoses
User Name
lost password?   |   register now

Thread: Chevy 350cu with th350 transmission not shifting after installing new vacum hoses Reply to Thread
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
04-27-2011 05:36 AM
75gmck25 There is a fairly large vacuum fitting on the back of the intake manifold behind the carburetor. You should have a vacuum line coming off this fitting to a vacuum T, and from that T you must have lines running to the HVAC canister and the TH350 modulator. You may also have other lines to the air intake control or EGR, but these first two are the minimum.

For the TH350 there there should be a short section of rubber line off the T fitting, then a steel tube that runs down the back of the engine and down to the TH350. An original steel line will be U-shaped on the modulator end, because the end of the vacuum modulator points at the back of the car. There will then be a short section of rubber line connecting the steel line to the modulator. You should not use rubber line for the entire connection because it is very near the exhaust heat, and it will probably soften and collapse under high vacuum.

If the original steel line is gone or there is a hole in it you can replace it with a new OEM one, or just buy steel tubing at the parts store and make a new line. The bends are not very sharp, so an inexpensive tubing bender can do the job.

04-26-2011 06:17 AM
eloc431962 Welcome to the site, and X2 on what mud bros said.

04-25-2011 08:27 PM
mud bros this little guy here needs to be connected to manifold vacuum.

it usually has a steel line that runs down to the trans behind the distributor
04-25-2011 07:43 PM
Chevy 350cu with th350 transmission not shifting after installing new vacum hoses

I have a 86 silverado. I was told it has a 350 with hydrualic rollers and a TH 350 tramsmsiion. Who ever worked on it before me did some stuff on it by cutting lines wires etc. I recently changed the plugs, wires and added some new vaccum lines. I think I changes a lines that effects the way it shifts now. It will not shift while driving. This is my main concern now so I can actuallydrive it to troubleehoot more.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -6. The time now is 05:02 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999 - 2012. All Rights Reserved.