1HZ A/C Compressor gave up the ghost today...

[lowtideride]

Alright, I have a 1991 HZJ73 that had the A/C go out today. I am almost positive the compressor is at fault. I came back and put a/c gauges on the system.... No movement. It read the same pressure on both gauges. The system was slowly starting to fade the past two months and today it seemed like it was over. It is Florida so I do use it A/C almost everyday of the year and it is my daily driver.

The system was still R-12, since I have to mess with the system I would like to swap to R-134a. From what I can tell there is a short and long version for the 1HZ and I assume all compressors being sold are for R-134a?

My original one is 88320-60340 but I am having some trouble weeding through all the misinformation on the net.

Thanks again!

 

[lowtideride]

Alright so I am going down the rabbit hole I will document to help others that might have the same issue. I ended up ordering a Denso 10PA15C 24v version, it looks like it was also used in a John Deere Tractor in the states. Next is to track down a dryer, expansion valve and maybe a condenser. Ill post photos and part numbers for all of it then.

 

[lowtideride]

Cit rep…
Expansion valve and dryer Denso part numbers for reference. Still waiting on the compressor to show up. I am a bit worried about where I ordered it from. It looks like a normal US based website but the pump was drop shipped out of china. The pictures showed a denso pump made in Japan, so I have a feeling it might be a counterfeit pump. Doesn’t help that 30% of the worlds counterfeit parts come out of china.

In either case I am going to run it for now, living with out a/c hasn’t been cool

 

[lowtideride]

Denso part numbers

 

[rick_d]

FYI, compressors can be easily rebuilt. In Tucson https://coolstreamac.com/ does it.

 

[SKULLYOTA]

@lowtideride I just converted my 1HZ to R134a and those part numbers for the drier and the expansion valve are what I used. I suspect my compressor is also going downhill as the low side pressure was too low when I had the manifold gauges connected, and yesterday during the 103 degree afternoon it felt barely cool at best.

Where did you order the 24V john deere compressor and did you have a PN?

EDIT: my research shows that a late 80's Corolla compressor is the same save for the 24V clutch possibly?

 

[lowtideride]

More part numbers… I also found the pressure check valve was available at my local Toyota dealership.

 

[lowtideride]

Here is where I am at… since converting to r134 I had to flush the entire system of the mineral oil the r12 system uses. Not really a fun task. This requires a flushing agent and dry compressed air. Also replacing all the orings on your ac system. Since I didn’t want to do this twice I also replaced the expansion valve and pressure sensor.

~I ordered what I was shown as a Denso pump. It is a knock off of it. So I ordered another one for a 12 system and am just going to swap the 24v clutch magneto to the 12v pump.

~If anyone wants to take a chance of my knock off pump they can have it for a 100 plus shipping. I just paid 240 for it.

~The real Denso pump should be here tomorrow. Hopefully I didn’t get taken advantage of again.

~The condenser is no longer available, from what I have read you should run a larger one when running an r134 system to make up for it’s less efficient cooling. I guess one should run one 30% larger but I don’t see how you could fit anything larger up there so for now the stock one will stay.

 

[lowtideride]

Also 10PA15C is the Denso style pump you have to run for the 1hz. Finding a 24v state side is a little hard. I think cruiser bros in Canada had one for 400ish but it also did not say it was a real Denso pump and looked like the Chinese one that I got.

 

[FJBen]

Also 10PA15C is the Denso style pump you have to run for the 1hz. Finding a 24v state side is a little hard. I think cruiser bros in Canada had one for 400ish but it also did not say it was a real Denso pump and looked like the Chinese one that I got.

Aren’t you basically just looking for the 24v clutch bs 12v? If your clutch is good you should be able to swap your 24v and chill.

 

[lowtideride]

Aren’t you basically just looking for the 24v clutch bs 12v? If your clutch is good you should be able to swap your 24v and chill.

Yes, and yes... That's why I ordered another 12v. I will be swapping out clutch parts to it. It would have been nice to find an all new 24v Denso unit though.

 

[lowtideride]

 

[Honger]

Here is where I am at… since converting to r134 I had to flush the entire system of the mineral oil the r12 system uses. Not really a fun task. This requires a flushing agent and dry compressed air. Also replacing all the orings on your ac system. Since I didn’t want to do this twice I also replaced the expansion valve and pressure sensor.

~I ordered what I was shown as a Denso pump. It is a knock off of it. So I ordered another one for a 12 system and am just going to swap the 24v clutch magneto to the 12v pump.

~If anyone wants to take a chance of my knock off pump they can have it for a 100 plus shipping. I just paid 240 for it.

~The real Denso pump should be here tomorrow. Hopefully I didn’t get taken advantage of again.

~The condenser is no longer available, from what I have read you should run a larger one when running an r134 system to make up for it’s less efficient cooling. I guess one should run one 30% larger but I don’t see how you could fit anything larger up there so for now the stock one will stay.

I didn't upsize/upgrade my condenser when upgrading from R12 to R134A... it's done just fine. Plenty cool here in Phoenix all summer long.

 

[lowtideride]

Got the real Denso one in and the 24v clutch swapped on.

 

[SKULLYOTA]

That compressor is pretty cheap on RockAuto too!

 

[lowtideride]

 

[lowtideride]

Just some A/C musings....

~I never found the exact amount of PAG oil to add to the compressor, nowhere in the FSM did it tell you just the overall amount for the system. I found some info online saying that it had 250cc filled from Denso, But no matter what way I turned it and spun it I got about 90ccs. The one I took out had ZEROcc in it

~The compressor came filled with oil for an R12 system so it had to be removed and filled with R134 PAG oil.

~Also I never found a solid number online by you have to multiple the R12 fill volume by .7 to .9 (varying info ). So, you need to fill the system with less R134 I ended up filling the system with 23oz of freon.

~The FSM said that the r12 system pressure was (low 29psi) and high (214psi). Now I am not sure this translates to R134, because when the low side was reading in the low 20s it was barley cooling but when I got to the low 30psi (on the low side) the ac temps reached 60 degrees in the cab at idle and mid 40s when driving.

~It took a long time to charge. I charged some of the system with the high side before turning the system on, even after that it took about an hour to charge the rest of the system off of the low side port.

Skull, I wish I would have found this Denso Part number earlier in my searches as it would have saved me hundreds of dollars. At the least I hope this helps someone else in the future.

~Al