AC troubles

[MANUCHAO]

My AC works great at idle blowing cold air, but once I'm on the hwy, or at speed on the road it starts to blow warm air...

I read up on this and could be as simple as being low on Freon , and or as complicated where my fan clutch is failing and not pulling enough air under load...

Any input is much appreciated...

 

[tmxmotorsports]

Sounds like it's low on freon. Start the truck turn the ac on high pop the hood get someone to slowly rev the engine and watch the compressor and see if it kicks out.

 

[Mace]

Go pick up a set of gauges and check the pressures.

Have you converted to R134 yet?

 

[MANUCHAO]

I'm going to another MUD member to check out gas levels...

Thanks four the input guys..!!

 

[Prairie Swamp]

Going down the road (over say 20 or 30 mph) your fan is just along for the ride as ram air has way more impact on heat pulled out of the condenser (or radiator.)

I'm not an AC expert but it seems odd that it would work sitting still but not going down the road. Electrical issue? Let us know what you find.

Eric

 

[Spike Strip]

At higher RPMs, the suction side drops. Possibly low refrigerant so it's triggering the low pressure switch at speed?

 

[MANUCHAO]

So, looks like the heater valve is not working a it should..
AC guys mentioned to block/ pinch the heater hose and run the truck.
His rationale is that at higher speeds the water pump is pushing mo water into the heater....

NOT only did it work, but the AC was really cold like never before..

I'm going to replace the heater valve and also add a manual inline shut off valve to the heater hose and see how this works out.

 

[Mace]

But on AC the heater core should not have any air cycling through it..

There is a bypass vent flap

 

[MANUCHAO]

@Mace Im thinking there might be more than miss the eye on my rig......
I replace that heater valve for a new one a few years back....
For it to have failed that way it has, is surprising...
Im going to install the inline shut off valve on the heater line since I already have a hose splice in place and, the 5.3 fitting on the water pump is ½" and the heater core fitting is ⅝".
Will see how it does...
I think I can survive without a heater during the summer months....
I also felt that my AC has never been up to 100% efficiency, until yesterday....

(New to me)
Some folks install a hose restrictor to limit the amount of coolant going into the heater core to force more coolant into the rad and to protect the heater core......

 

[Spike Strip]

Frank, that NAPA valve does not look like the OE unit. May work, but the valve is still available from Toyota. I know you've got a conversion, but still using the stock valve ?

That heater core restrictor is a new one on me... But being in So. Cal ... AC way more necessary.

 

[MANUCHAO]

@Spike Strip I'm putting that NAPA valve in addition to replacing (down the road) the Toyota OEM heater valve...

 

[Spike Strip]

Ah, ok. But that's a cable-valve. I thought you'd want something like the one I used when my valve went bad.

Amazon.com: Four Seasons 84707 Shut-Off Valve: Automotive

 

[MANUCHAO]

I looked at that very same valve, but again...
Having a valve that fits the dimensions on the heater hose splice that is already in place makes is much easier to replace....
It will be shot off until it starts to get cold again...
I'll probably put some tape on top of the actuator to keep it from opening...
I'll post pics of the before and after....
that toyota heater valve was not cheap at $117, but better to have it at that price than NLA...... and that day will come

 

[Spike Strip]

Wow. They went up...

 

[TexasBlue]

I just bought front heater valve assy from Ebay for $78 with free shipping. It's OEM

 

[TexasBlue]

Cityracer has them $68. Just found it..