i know its a vacume leak thats the problem cause when i mash on the gas it blows out the defrost but if i turn off the od it comes back does anyone have a sceth of vacume hoses and stuff on a 95 f150 with i-6?

Thanks Evan

 

My 1990 F250 5.8L just started to do the same thing....
Wow, if its a vaccum leak where is the hose?
I thought it would be behind the dashboard someplace.

Thanks! in advance for any help.

Larry

 

It is going to be vacuum leak and could be under the dash or under the hood. The vacuum distribution for our model trucks begins on top of the upper intake.

Evan,

E-mail me and I will send you what I have on the line routes.

Mike

93' F-150 Ext Cab 5.0L E4OD, MSD, K&N, 31x10.50's

 

I have a 1990 E-250 with a 4.9 and it does the same, if you have any suggestions at all please pass them along........thanks!

Bill

 

 

OK my 93 F-150 just did the SAME thing and it cost me a upgrade from R-12 to R134a...sheesh my bad trusting a local wrench..instead of my own senses! Sooooo...what is the vacuum routing...took me all afternoon to dismantle the front dash stinking Chiltons manual is worth...diddly.....anyway would really appreciate the help.
Well here are the symptoms:
Normal A/C.....ok
Max A/C.....no change in air flow and then at speed flops between defrost and vents.
All other positions work fine......Man it's hot here in south Texas....TIA for the help.

Chinookman

6-turning-two-burning--and the smell of JP-4....ahhhhh

 

I have found that alot of times it is the one way check valve coming out of the vacume canister that causes the problem. but realy it could be any where in the system.

Good luck, get a hand vacume tester and gauge set up it will help out alot in testing.

Scott

 

hey my truck the max was no differt then the the ac. and neather were very cold to night i took it for a drive and in idle it was was making a terrible nosie took it to frends (X shop teacher fellow 97 150 owner)he said it was the pump on the ac.

 

I saw a post last week that was refering to a deterioated white colored vacuum line that comes from the vac. relay/motor under the dash on the passenger side. Replacement of this vac line fixed his problem which sounded similar to yours....if you do a search on "vacuum motor" it should show that post......

 

go down to post "A/C fixed.....you guys rock" may be the exact same prob. you have...

 

:-X12 Yipper, I'm a happy camper! used the Mity-Vac lil'ol hand pump and started troubleshooting. The white vacuuum line OUTSIDE under the hood was flaky. Clipped about 4 inches off and replaced and voila! MAX A/C to the max, talking 'bout 44 deg. f. here now it is good! This is s cool place plan on hanging out here until I trade her in fer a new Dodge 3/4 ton...watch the rocks now!
want that Hemi-baaaaadly! later all....Chinookman

six-a-turning-two-a-burning...

 

Where is the line under the dash? I have checked all the lines under the hood and they all are good.....


Thanks,

Larry

 

>Where is the line under the dash? I have checked all the
>lines under the hood and they all are good.....
>
>
>Thanks,
>
>Larry
Larry, start with the white vacuum line at the vacuum motor above the blower motor assy. IF it is not flakey and powder like on the surface then your right on. Remove the glove compartment, and to the bottom right it will help you see the three vacuum lines they tie in with a small plastic splice.

I removed the radio, then the "XLT" trim that is mounted along the dash between the radio and A/C controls, it popped out, this allowed access to the two mounting screws for the A/C controller. Once that was accessed then it was a matter of using the vacuum pump to pump down a vacuum or pressure and see if the acuator motor under the hood responds. If it does not then it's a matter of tracing at different points where the source of the leak may be.

best regards

 

https://www.ford-trucks.com/dcforum/DCForumID39/4723.html

Good Luck