Engine A/C QUESTION

Mustang5L5 · May 5, 2026

The kit is great of you need one stop shopping, but you can likely grab all those parts, except the manifolds, from RockAuto for cheaper. They are pretty much the same brands they sell.

Accumulator will frost up depending on ambient conditions and this could be considered normal.

If you suspect your evap core is compromised, or even dirty internally, replace it. Would hate to see contaminates go downstream and plug up other components. Since AC work is expensive in general it's best to take an replace all approach to have the best luck of success.

I have seen folks remove the evap and flush it. You can certainly go that route to, but since it's out it wouldn't be a bad idea to replace it either.

NXcoupe · May 5, 2026

Noobz347 said:
Your [clutch cycling pressure switch] may be bad or intermittent (if it's shooting out of the relief valve):

Closes at 45 psi and reopens at 24.5 +/- 1.5 psi

V8 Foxes don't cycle the clutch. That is the low pressure cut off switch. It is there to protect the compressor from operating with not enough refrigerant in the system to move oil into the compressor. If your compressor is cycling, it's low on freon.

Mindseye007 · May 5, 2026

NXcoupe said:
V8 Foxes don't cycle the clutch. That is the low pressure cut off switch. It is there to protect the compressor from operating with not enough refrigerant in the system to move oil into the compressor. If your compressor is cycling, it's low on freon.

What if the compressor does not cycle at all ? Out of freon? Compressor cooked?

Mustang5L5 · May 6, 2026

Mindseye007 said:
What if the compressor does not cycle at all ? Out of freon? Compressor cooked?

If you jump out the low pressure cutoff, and the clutch doesn't engage it's likely electrical. Either the circuit of the compressor clutch itself. You'd have to check the wiring.

A properly charged system shouldn't cycle under most ambient conditions. Ambient temp has a huge role in system pressures and most situations where you run your AC should keep the low side pressure up high enough to prevent any cycling.

The only time the system may potentially cycle is if being used in cooler temps. Defrost for example on a 45-50 degree day. In this situation system pressures will be lower and the low side may dip under the min pressure to set off the low-pressure cutoff switch. This is exacerbated by the fact that many folks don't adjust the low pressure cutoff when they convert to R-134a and leave it at 25psi.

Mindseye007 · May 22, 2026

Mustang5L5 said:
If you jump out the low pressure cutoff, and the clutch doesn't engage it's likely electrical. Either the circuit of the compressor clutch itself. You'd have to check the wiring.

A properly charged system shouldn't cycle under most ambient conditions. Ambient temp has a huge role in system pressures and most situations where you run your AC should keep the low side pressure up high enough to prevent any cycling.

The only time the system may potentially cycle is if being used in cooler temps. Defrost for example on a 45-50 degree day. In this situation system pressures will be lower and the low side may dip under the min pressure to set off the low-pressure cutoff switch. This is exacerbated by the fact that many folks don't adjust the low pressure cutoff when they convert to R-134a and leave it at 25psi.

Ok trying to take my accumulator off there is that top big nut that conects to the evaporator and I used a Cresent wrench and it will not budge...this accumulator is 7 years old and it leaks so time for a new one, how do I get it off. I'm going to do my heater core and evaporator core perfect weather to do it and it's my first time doing it so and i have watched alot of youtube videos on how to do it. And so far that dam accumulator nut will not budge. Would heating up the nut with a heat gun work to help it break loose?

General karthief · May 25, 2026

Yes, no flames.

Mustang5L5 · May 26, 2026

Pen fluid. Spray and let sit. Big wrench. No flames on a pressured system with flammable gas.

Mindseye007 · May 26, 2026

Mustang5L5 said:
Pen fluid. Spray and let sit. Big wrench. No flames on a pressured system with flammable gas.

whaT IS the best pen fluid?

Liquid Wrench Penetrating fluid?

View: https://www.youtube.com/watch?v=xUEob2oAKVs&t=560s

General karthief · May 27, 2026

Mindseye007 said:
whaT IS the best pen fluid?

Liquid Wrench Penetrating fluid?
View: https://www.youtube.com/watch?v=xUEob2oAKVs&t=560s

whatever you have on hand at the time

Mustang5L5 · May 27, 2026

I like PB blaster because it's what I have.

nickyb · May 27, 2026

Whatever oil you use ,try tapping the wrench with a BFH as this will shock the out of it and break it loose.
And by tapping I mean wack it like it owes you money.

Mindseye007 · May 31, 2026

Mustang5L5 said:
Pen fluid. Spray and let sit. Big wrench. No flames on a pressured system with flammable gas.

You need 2 crescent wrenches cuz there is a small nut behind the big nut, will it be under pressure? Pulled the botom ac line off the evaporator and I thought the freon all leaked our when it spayed out of the pressure relief manifold when it popped , cuz a tonne of freon sprayed out, man was I wrong when I pulled the line off it sprayed out scary stuff could have died. Should have had it checked before and had all the freon evacuated out . Is that expensive to get done? I just want the dam hvac box out so I can replace the heater core and evaporator. sucks not having no heat or A/C, but I do love crusing with the windows down to hear the exhaust sound so sweet. I'll get a mechanic to install the new lines and manfolds might even get a new compressor all from lmr and charge it up again.

Engine A/C QUESTION

Mustang5L5

That is…until I whipped out my Bissell

NXcoupe

Active Member

Mindseye007

Mustang5L5

That is…until I whipped out my Bissell

Mindseye007

General karthief

wonder how much it would cost to ship you a pair

Mustang5L5

That is…until I whipped out my Bissell

Mindseye007

Liquid Wrench Penetrating fluid?

General karthief

wonder how much it would cost to ship you a pair

Liquid Wrench Penetrating fluid?

Mustang5L5

That is…until I whipped out my Bissell

nickyb

I gotta say i never painted my nuts, Never Ever

Mindseye007

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That is…until I whipped out my Bissell

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That is…until I whipped out my Bissell

wonder how much it would cost to ship you a pair

That is…until I whipped out my Bissell

Liquid Wrench Penetrating fluid?​

wonder how much it would cost to ship you a pair

Liquid Wrench Penetrating fluid?​

That is…until I whipped out my Bissell

I gotta say i never painted my nuts, Never Ever

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