Fixed A/C in the Mustang

[bdcardinal]

Picked up a 1995 Mustang GT from a friend of mine a couple weeks ago. One of the things he said in the sale was the A/C didn't work. No matter what the setting was on the mode switch it would only blow out the defrost. He said he had a quote from a couple local independents for a few thousand dollars to pull the dash and possibly replace the compressor, condenser and accumulator due to it only blowing hot.

I mentioned it to a couple of our electrical / diag techs at work and they both said "vacuum leak trace all your lines."

Fast forward to Sunday when I was changing the oil, I found a broken vacuum line connector that went into the firewall. I didnt have anything at home, so the next day I grabbed some vacuum connectors and some bulk line and traced where that line should go. I made an entire new line replacing the brittle 17 year old factory line. Got in the car and I had A/c out of all modes along with hot and cold. So for under $2 in vacuum t's and bulk line I fixed the A/C.

here are some real bad iPhail pics showing the broken line and my MacGyver fix.

This is the vacuum tree by the master cylinder. You can see the hard line.

This is the line going into the dash. I used "t" connectors in-case I ever need an easy vacuum source.

 

[hardcore302]

Nice! Noe you can use the money you saved on the AC fix and invest in a Trick Flow top end! Or some AFR heads with a cobra intake and alphabet cam! DOOOO ITTTTTTTTTTTTT

 

[Colt45ws]

Nice. Thats such a duh. As soon as I heard defrost only I knew what the problem was. Thousands to pull the dash and replace the whole A/C system? Puhlese. Ripoff artists.

 

[FirstNissan]

Great job with the diagnosis and fix. AC systems are one area that I draw the line on trying to DIY. This helped inspire some confidence.

 

[bdcardinal]

A lot comes down to reading the manual. I am lucky and have access to a lot of resources most people don't.

We were joking at work about it that if a shop had pulled the dash and replaced everything and the vacuum line fixed it the customer would have never known.

O and hardcore, I am planning on building a motor using a FRPP BOSS 302 block, possibly a Probe 347 rotating assembly, Trickflow HCI. I have a bunch of Maximum Motorsports parts in my garage and am planning on ordering the rest of the Maximum Grip package.

 

[hardcore302]

Originally Posted By: bdcardinal
A lot comes down to reading the manual. I am lucky and have access to a lot of resources most people don't.

We were joking at work about it that if a shop had pulled the dash and replaced everything and the vacuum line fixed it the customer would have never known.

O and hardcore, I am planning on building a motor using a FRPP BOSS 302 block, possibly a Probe 347 rotating assembly, Trickflow HCI. I have a bunch of Maximum Motorsports parts in my garage and am planning on ordering the rest of the Maximum Grip package.


That grip in a box setup is nice. I have used BMR pieces before.
If you're gonna go with trick flow and a 347, use the stage 2 cam and the track heat heads/intake. will suit the size better. good luck! pics when you finish!

 

[chrome]

OK, I don't think I understand. Does the vacuum hose supply something that is required for the A/C to work? Actuators for mixing flaps etc?

 

[bdcardinal]

Originally Posted By: chrome
OK, I don't think I understand. Does the vacuum hose supply something that is required for the A/C to work? Actuators for mixing flaps etc?


Yes the blend door motors are vacuum actuated on this model. Ford's system defaults to defrost if it loses vacuum (think worst cast scenario). Knowing that I just looked for the main source of vacuum for the system.

 

[wirelessF]

It's the same on my 2004 F250. You have that hissing sound when you switch modes.

If anything goes wrong, I'll keep this in mind.

 

[nwjones18]

Yep my mustang did the same thing and had the same problem! Nice when its an easy fix.

 

[KrisZ]

Isn't it amazing what can be done once you lift the hood up?

 

[Schmoe]

My truck is about the same thing. Vacuum for lots of things, including the shift on the fly 4X4 mode.

 

[OVERKILL]

Originally Posted By: bdcardinal
A lot comes down to reading the manual. I am lucky and have access to a lot of resources most people don't.

We were joking at work about it that if a shop had pulled the dash and replaced everything and the vacuum line fixed it the customer would have never known.

O and hardcore, I am planning on building a motor using a FRPP BOSS 302 block, possibly a Probe 347 rotating assembly, Trickflow HCI. I have a bunch of Maximum Motorsports parts in my garage and am planning on ordering the rest of the Maximum Grip package.


If going that route, give Woody a call at fordstrokers, he's got a great reputation for quality work. He'll likely also recommend you get a custom cam for that setup and the matching valvetrain components to compliment it (upgraded springs and the like).

He's on SBFTech if you want to chat with him.

 

[sleddriver]

Nice catch & great fix!

My brothers Expedition did the same thing. We traced the vac line underneath the battery and sure enough it was split. Now he has cold air out of the vents. Unfortunately he also has a vac leak in the brake booster: It constantly hisses until he steps on the brake.

It's been over a year and he still hasn't fixed it. Bet he's taking quite a hit on his gas mileage. . . .

 

[Colt45ws]

Wanna hear something retarded?
A lot of the older powerstroke models had the same vacuum operated blend doors as the gas models. To get around the fact that the engine does not have any vacuum, Ford installed a little electric vacuum pump.
At some point, they got smart and made the whole system electric.

 

[bdcardinal]

Haha ya those vacuum pumps are big sellers.

 

[Jarlaxle]

Originally Posted By: Colt45ws
Wanna hear something retarded?
A lot of the older powerstroke models had the same vacuum operated blend doors as the gas models. To get around the fact that the engine does not have any vacuum, Ford installed a little electric vacuum pump.
At some point, they got smart and made the whole system electric.


I recall the diesel vacuum pumps were actually belt driven...on the 7.3 PowerStroke vans, it mounted on the top of the engine, driver's side above the PS pump.