Repair guides and support for C/K pickup trucks sold by General Motors under the GMC brand, including the GMC Sierra.

26 Questions View all

Locate vacuum hose by transmission

Locate vacuum line to transmission

Answer this question I have this problem too

Is this a good question?

Score 2

Comments:

Hello everyone I have a gmc 1500 4x4. I replace my trany and as doing so I don't know were the black rubber hoes connect to I do know that one go's to the transfer case and the other one gos to the tranmission but don't know were the other ends go to

And they both have plugsat the end of them I do remember are i think above the transmission there was a bracket they was connect to some please help me 28th pic

by

Same problem, tranny won't shift into third . 1989 Chevy Silverado. 4x4 5.7 motor . i need some kind advice on what i should do as far as do it myself or take it to shop.

by

@marciano68 You can start by checking the fluid levels in the trans when the truck is warmed up to normal operating temps.the trans fluid level is checked with the engine running in park . If its low it may be a good time to change the fluid and filter. If this brings no joy then you may need to seek professional help

by

Can u show me a picture of we're it goes

by

http://67-72chevytrucks.com/vboard/attac...

In this picture the line is steal but runs from the throttle body down to the tail of the trans. Its the silver line next to the trans dipstick tube

by

Add a comment
New Battery = Faster iPhone
Fix Kits starting at $16.99

2 Answers

Most Helpful Answer

The year range is pretty non specific.

If the truck has a vacuum hose to the transmission (to the vacuum modulator), the line will be a metal tube attached to the large tube that the transmission dipstick is in. It will come up and connect to a hose that will run to the base of the carburetor.

The function of this line and the modulator it goes to, is to give the transmission some sense of how much throttle is being applied during a shift to make the shifts softer or harder depending on load. The transmission will work without this line, but the shifts will be hard as if the throttle was all the way to the floor.

If the hose is broken or missing, there will also be a vacuum leak at the carburetor, causing a rough/high idle and possible an intermittent backfire.

If the truck is new enough, the transmission will be electronic and not have a vacuum modulator at all, and will have a plug with several wires connected to it on the drivers side.

Was this answer helpful?

Score 3

Comments:

i was wondering if the transmission has an overflow tube(rubber)cuz if not then i need to know where it goes. reverse is not working, but it will back up in 4 wheel drive low only when its cold. i put tranny fluid in yesterday nothing showing on the dip stick and it started leaking out that rubber tubing. the tubing in on top of the tranny itself. it s 700r4 in 1991 chevy truck 4x4. can u please help me?

by

Add a comment

where is the vaccum hose?

Was this answer helpful?

Score 0
Add a comment

Add your answer

bagwelltanya16 will be eternally grateful.
View Statistics:

Past 24 Hours: 27

Past 7 Days: 180

Past 30 Days: 888

All Time: 5,769