Here I am

Engine/Transmission (1998.5 - 2002) AC compressor seals leaking...

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff
Status
Not open for further replies.
Which AC compressor to buy as replacement?

So I need a new AC compressor for my 98.5 CTD 5.9L 24 valve. I have two questions:

  1. Are there brands to be avoided or that users recommend? Or just go with factory replacement? Or will any 6858​9 do...
  2. What else should be replaced at the same time to avoid further trouble?

I have seen prices ranging from $120 to $500 for new AC compressor w/ clutch. Why so much variation if not quality issue?
OK, that was three questions...

Thanks,
:confused:
 
Last edited:
The Factory compressor is a Denso unit, and is relatively good quality.
If you replace the compressor, and you plan on keeping your truck, you should replace it with another Denso unit. In my opinion, the other brands are no where as good. GPD and Four Seasons are not as good as the Denso units.

If you replace the compressor, you need to replace the orifice line and the accumulator. The compressor comes with the expansion valve.
From Napa, the Denso compressor is about $300, the orifice is about $35, and the accumulator is about $30.
From Rock Auto, the Denso compressor is about $200 , the orifice is about $22, and the accumulator ranges from $13 to $20 (get the more expensive unit).
If you look at the P#s between NAPA and Rock Auto, you can match the same components (the P#s will somewhat line up).

If you can wait a few days, get them from Rock Auto. All the new lines and parts will come with the necessary o-rings/seals, so you do not need to buy new ones.
These systems use PAG 100 oil, ensure you put oil back into the system.

You might want to consider replacing the condenser as well. it is exposed to rocks, and all other types of road debris and is probably pretty beaten up by now. Get a Spectra unit, for about $74.
There is one more hard/soft line, which goes from the compressor up to the condenser and from the compressor to the evaporator (it is shaped like a Y and has foil insulation wrapped around it). It is around $53.

By replacing these parts, you will have replaced all the parts under the hood, leaving only the evaporator in the dash left. What the good part is about doing it like this, you do not have to fight with the fittings, with the exception of the two which go into the evaporator. Just take a die grinder and cut apart the old lines.
with the two that are left going into the evaporator, with the line cut-off at the accumulator, and the other line to the compressor cut, you can insert the extraction tool, and can now freely rotate the line, which will make pulling them apart 100% easier (still a PITA though).

Dumb question, but do you have the tools to take apart the fittings? They are the same as fuel line disconnect tools, Astro tools makes a good set of machined aluminum. I would not try the plastic ones, they will probably break. These fittings are a major PITA to get apart. They take a lot of patients, but will come apart. The website below is just for reference. This kit will work, but shop around. There are other kits out there, but this is the one I personally use. You will need 3 or 4 different size tools to get all the fittings, including the two largest ones in this kit for the lines to the evaporator.
http://www.thetoolwarehouse.net/p-27909-6-pc-ac-and-fuel-line-disconnect.aspx


If your compressor burned up due to lack of oil, you will want to flush the system. You can get flush kits online for not too much, check E-Bay. Technically, you should always flush the system, but if you are replacing everything under, and the compressor has not burned up, then you can get away with not flushing the system.


Ensure that you vacuum the system down for at least 30 min down to -30 in mg to ensure that any residual in the system is pulled out / evaporated. You should use a micron gauge (if you have one) and pull the system down to below 100 microns (depending on your vacuum, this will take about 30 min). Leave a vacuum on the system for at least 2 hours after you have pulled the system down (with the pump and gauges turned off) to see if there are any leaks.

Have you replaced the evaporator before on this truck?
If not, you might want to consider that as well (not fun, your dash will crack and is a pain). Do your heater core at the same time, and probably the blower motor as wel.

On a side note, R134a is getting expensive from the auto parts stores. If you buy a few of the little cans from the Auto parts store, you will be out $100.
You can buy a 30lb can for $86 from e-bay. Just as an FYI, you do not need a license to buy 134a.
http://www.ebay.com/itm/NEW-factory...Parts_Accessories&hash=item4aca22e961&vxp=mtr

If you have any AC questions, please let me know, I will try and help you out where I can. Overall, this job is not too difficult, it just takes a few special tools.
If you get everything from Rock Auto, you are looking at about $400 for the parts (with their 1927232316877708 discount code).
Freon and Oil will run you about $100 for a 30 lb keg of r134a and 2oz of PAG 100.
The Astro tool kit is about $35.

If you take this to a shop, you are probably looking at $1000 to $1200 for this work.


A few other special tools you will need:
Vacuum manifold gauge set, preferably with gauges that read R134a temps/pressures.
Vacuum pump which can pull 30 in mg.
Micron Gauge (optional, but good to know that the system is pulled down)
 
:--)

There goes my $ I set aside for a program chip! I assume the instructions were given with parts replacement in order of priority, first being highest, last (evaporator) being lowest (my blower motor is new and I'm not sure about anything else because I've just had the truck a little over a year). The compressor runs, it just leaks like a sieve. I assume this means it is not burned up and I won't need to flush at least...

Does replacing the heater core make it heat up faster in the cab on cold mornings, or should I get an inverter and plug in a foot heater? I "commute" 5 miles to work and the temp needle doesn't even budge off the low peg.

Thank you very much Carl, for all the great info! Looks like I have some shopping to do.

Best regards, and have a great 2014!

- Steve from Insitu
 
If the compressor just runs, but leaks, you can try putting in Super Seal. In a worst case, either the leak will continue or the compressor will freeze, but I have seen this stuff stop leaks in a lot of systems.
http://www.cliplight.com/automotive/super-seal-additives/

You can buy this at NAPA and Advance for around $50-$60. I am sure the other auto parts stores sell this as well. These kits comes in a sealed plastic clam shell and includes a charging hose, so you can put the stuff in the system (read the instructions carefully, you will need to shake up the can, and charge with it upside down). I would not recommend putting it into a brand new system, but it might save you a lot of effort. It is not like normal stop leak, which resembles a foam material. The super seal remains a liquid/gas until it comes into contact with Oxygen, then it solidifies, which will seal most holes, including those in metal.

I have used this in many cars over the years, and their other products to stop leaks in R22 systems. I have only had bad luck one time with the Super Seal, and it was on another Dodge, with the AC on its last legs. It solidified in the compressor, and we had to replace the compressor. I did not really care, as the system was at the end of its life.

If you go the route of the Super Seal, get a 12 oz can of r134a Freon. You will want to put this into the system just after you load the Super Seal. This will keep the charging port from becoming clogged.

If the compressor is building pressure, than it still works, and is not burned up. Those Denso compressors are almost bullet proof, as long as they have oil in them. If you do get a little can, ensure it has some oil in it. usually, most of these cans include 1 oz of oil.
I would not worry about flushing it unless something really bad happened to the compressor.

What most people do not realize, over time, the hoses break down, and the oil will seep out of the hoses. With older R12 systems, the oil used was Mineral oil. Mineral oil does not evaporate quickly, and as it seeps through the hoses, will show an oily residue, and will collect dust. This makes finding leaky hoses easy.

With R134a systems, PAG (Polyalkylene Glycol) oil is used. PAG evaporates much more quickly than Mineral oil, and therefore, it is much more difficult to spot leaky hoses. Over time, the oil in the system will eventually seep/leak out, causing the system to run out of oil. Once it is out of oil, it is no different than running your truck with out oil, the compressor will eventually burn up.

Just as an FYI:
PAG and Mineral oils are not compatible; this is why an R12 conversion to 134a requires a flush during the conversion.
Do not put too much oil in the system, it is just as bad as not enough oil.


For the heater core, the reason for replacement, they are only about $30, and you have to pull the dashboard out of the truck to get to the evaporator. The evap is in the middle of the black box, and in the first attached photo, you can see the aluminumum tubes sticking out towards the bed of mulch in the background. You can see these tubes stick through your firewall into the engine compartment. The copper colored item is the heater core. While you have the truck apart, you might as well replace this item. You do not want to do this job twice.
Heater Box.jpg
Heater in truck.jpg


It is likely that changing the heater core will aid in getting heat faster (assuming you get an OEM copper/bronze style heater core). It is not because of the heater core being a better design, instead, it is because the old heater core likely has a buildup of sediment on its inside, which are a combination of old anti-freeze, and contaminates from water.
If this is an issue, you can try and flush the cooling system a few times. It will likely get the grime out of the heater core.

Just my $0.02 on the heater core, if you do replace it, buy the OEM quality item (copper/bronze), without the swivel heads. The aluminum cores do not transfer heat as well, and it will take longer to get heat.
You could also put a cardboard box in between the radiator and the intercooler. It will heat up faster. :D

Heater Box.jpg


Heater in truck.jpg
 
AC Clutch

You have any instruction for replacing just the AC Clutch 98.5 24valve. Wont engage and the thingy on the end of pulley kinda loose.
Pulley bearings seem O.K. ie still runs free and compressor will turn free by hand.
Thanks in advance if you can help a shade tree mechanic:confused:
W.D.
 
google it, I just replaced my compressor, accumulator & restricter tube (refrigerant control tube). I contemplated on changing just the clutch, but I went with a full repair. I found info for doing just the clutch online with a google search, but mine is a 2007 CTD.
 
First, yes, I do work on A/C systems and yes, I've spent thousands in equipment to do so.

PLEASE do NOT use any type of sealant in your A/C system. This is a VERY bad idea. If the system is under factory warranty, it won't be anymore. ALL major automotive manufactures I've dealt with will void any A/C warranty if sealant is added. To properly repair the system "EVERYTHING" will have to be replaced. Very expensive to pay someone to do that.

For a mechanic, it will also ruin his equipment and void that warranty too.

I test for sealant before I work on a vehicle. If I even suspect sealant is in the system I close the hood, no charge to the customer, and give them the bad news and also I will not work on the system - ever.

If you mechanic says it is ok to use, ask him why and if there have been problems with it. Then ask if he specializes in A/C and has the ability to:
- knows how this specific sealant works.
- detect sealants.
- determine the purity of the refrigerant in the system as well as what is really there.
- know how to use a micron gauge.

There are 2 types of sealant. Bad one - rubber seal sweller, and worse - stuff that hardens with moisture and/or air.

Now you say - if it is bad, why do they sell it. Easy - to make money. Just like many things you can buy, but are not necessarily wise to use.

If you have questions, ask, I'll do my best to answer. No, I'm not going to get into a debate. If you want to use the stuff go right ahead, it will not affect me.
 
Last edited:
The crap they sell in the auto part stores, is just that, "Crap". I bought a 30lb jug of 134a, just to get real refrigerant, the refrigerant they sell in the parts houses claim to have additives that cures all. I had to purchase additional PAG 46 oil to complete my compressor replacement and had a hard time finding oil with UV dye ONLY. Again the oil also has additives with miracle cures.
 
Status
Not open for further replies.
Back
Top