Engine Foxbody Mustang A/C Compressor Reseal - Nippon-Denso 6P148A


That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
I plan on rebuilding a factory NipponDenso 6P148A Compressor. This thread will show details of that progress. It will be completed in stages, so I recommend clicking the watch button at the top right to get future updates as this won't be done all at once.

Initial thread will be a bit all over the place as I perform various tasks in rebuilding the compressor. Just bear with me.

My compressor seems ok at first glance. The Clutch bearing is failing, so that will also be replaced. I will detail out the clutch replacement, part numbers, and the AC compressor rebuild with part numbers for that as well.

This thread will be locked for the moment while I build it. Once I've added pics and enough data, I will open it up for discussion. For now, I just want to get my formatting

this is more of a reseal than a rebuild. I’ve been unable to locate misc hard parts for inside the compressor, so if you find your piston is bad or the bores are all corroded, not much you can do other than find a new compressor. This how-to is more on fixing leaks and cleaning up/lubricating the internals and will feature a body seal kit and a shaft seal kit.

Edit: made some videos on this process

Part 1: disassembly

View: https://youtu.be/-bW17DxVfuM

Part 2: reassembly

View: https://youtu.be/fIfR80lsL_0
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AC clutch Removal and replacement

See this thread

A/C clutch part numbers

Hub Disk:
E43Z-19D786-A (Motorcraft YB-289-A)

A/C pulley:
E2ZH-19D784-A (Motorcraft YB-316A) This part comes with a new bearing installed

Clutch Coil:
E8DH-19D798-A (Motorcraft YB-358-A)

Clutch pulley bearing:
Nachi 40BGS11DS

See post #7 for information on the o-rings and seal kit for the compressor
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Service PDF.

Good information in here regarding procedure for tearing down and misc information, oil capacity, specialized tools

Specialized tools "required:" These may be able to be substituted. OTC or Rotunda. You may not even need them and I was able to fully disassemble without any tools. The shaft key tool might be needed depending on how tight your key is.

Housing Clamp - T81P-19623-LH
Shaft key remover - T81P-19623-NH
Valve plate remover - T81P-19623-PH
Shaft Seal Remover - T81P-19623-OH
Shaft Seal Seat installer - T81P-19623-C

See post #7 for compressor o-ring kits


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Teardown commences. A 6MM Allen wrench is used for the top manifolds and front housing bolts. The front bolts use one-time use copper crush washers behind the heads, so make sure these are removed

manifolds removed

These feature 4 o-rings which will be removed and replaced by the rebuild kit.


on one manifold is a pressure relief port. This can be removed and replaced although I do not have a compatible replacement at this time. I believe the original valve is a Motorcraft YF-50, which is discontinued. Motorcraft YF-52 comes up as compatible, but it looks completely different so not sure if it truly is.

The high pressure blowoff is set to 450psi. If it ruptures, you need a new one.


Edit: LMR has replacements for these

Also here

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Before you remove the front cover, the shaft key needs to be removed. You can try to be creative or just get your hands on the OTC T81P-19623-NH tool


I could t get it out without damaging it, so I ordered the tool. Stay tuned
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You can remove the top cover without removing the key, but once again I was unable to remove the shaft key with hand tools. It’s in there. You need it out to install the new shaft seal

EDIT: See post #10. I was able to get it out without the tool


once off, you can use a screwdriver to pop the old seal out of the front cover. No need to get the otc tool.

a small metal clip holds this front wick in. Bend it up and pull it out. The purpose of this wick is to capture and route any oil that makes it past the shaft seal down and away from the clutch pulley assembly. You’ll notice how it routes down and behind it, channeling oil away. Needless to say, if this is saturated with oil, you likely have a shaft seal issue.


A small tug on the metal clip can remove it to get it out of your way
gasket can then be removed. This is included in new rebuild kit

make sure you remove the two pins in the cover and save them somewhere secure
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As for rebuild kits, this is what I am using from century air

part number: MT2140

this is a basic rebuild kit that comes with 4 manifold o-rings, 3 body o rings, valve gaskets and new brass crush washers for the body bolts


You also want the shaft seal kit

part number : SK-753N

These are the basic rebuild components. As you can see this won’t repair or replace many of the internal hard parts, so if you compressor is in bad shape, you may want to seek out a new one to rebuild. These kits just repair leaks and assume there is still a good coating of lubricant inside the compressor and no corrosion.

if you need o-rings and springs for the rest of the ac system, you can use this. Not for the compressor

there is also some redundancy with the two kits. As you can see you’ll have extra brass crush washers and one extra body o ring

one final note. Make sure you have refrigeration lubricant that matches your gas on hand for assembly, as well as rubber gloves

EDIT: Looks like the kits from Century Air are discontinued. I was able to find rebuild kits elsewhere just google searching

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Here is your compressor exploded view. Not shown is the 3rd o-ring which is located in the middle of the body of the compressor which is accessed by splitting the body. See my later post showing this
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Continuing on. A couple taps with a rubber mallet and the rear plate comes off. The valve plate here is marked with a R. I suggest you bag it once removed. We can relube it when we go to assemble. There is a gasket and an o-ring here to remove

There is no need to remove the nuts and disassemble this valve plate further
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I was able to get the shaft key out wothout the special tool. A pair of channel locks levered it out.


Front valve plate is similar to the rear. It’s marked with an F. Set aside for now

Take note of the shaft and how rusty it is. The shaft seal will sit here so you really want to make sure this surface is smooth. You may need to disassemble the shaft/pistons to remove the shaft fully to polish it up. You do not want a leak here so do your best to shine this up.
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Now we have the Pistons and inner body. It’s 3 moving postons on a swash plate, but three on each side so technically 6 pistons


a couple taps with rubber mallet and some leverage on the manifold ports and you can split the body

Rear half slides right off


this gives you access to the 3rd o-ring. At this point you don’t really need to go further, but we will for the sake of exploration.

PLEASE NOTE: If you are just resealing the compressor, replace this o-ring and then start reassembling. No need to pull the Pistons really unless your unit needs cleaning or you might need to replace the inner bearing. You might want to wipe it down to remove all traces of old oil depending on what oil you plan on using for your refrigerant.

If your shaft needs to be cleaned up, it might be best to proceed further and keep on disassembling.

Proceeding and pulling the pistons and reassembly isn’t difficult, but might require a little trial and error to hold the three pistons while you insert them into the bores.
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The Pistons are pretty simple. They feature a ball and cup which rides on the swash plate

the seals are plastic c-clips and split at one part. No replacements as I can see. Inspect and lubricate and leave them alone


The contact plates are just a ball bearing and copper/brass cup
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Hardware. Most likely you can use what you have. If you’ve painted or powdercoated the housing you might want new bolts.

M8 x 1.25 x 20mm Allen head - 4 bolts

M8 x 1.25 x 147mm Allen Head - 6 bolts

The body bolts are an odd size. You won’t find equivalent 147mm long bolts and I couldn’t find 145mm. 150mm are a tad long and bottom out, but what I ended up doing was threading an M8 nut on and cutting 3-4mm off the bolt and then cleaning up the thread.

I went stainless of course
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Refrigerant oil:

NOTE: This is written specific to R12. You'll need to substitute the proper oil for R-134a. I'm posting this as reference as to fluid capacity.


If you’ll notice, the system capacity is 10 ounces (8 ounces for 89+) and a new reman compressor ships with 10. There is a procedure for avoiding overcharging the oil.

if you are building a totally new system this is easy as you just fill per the directions above. If you are resealing the compressor only, you need to measure prior to disassembling.

As to what fluid yo use, that all depends on what you are doing. if you are resealing the compressor, we have to assume it will be cleaned well enough to be rid of all mineral oil other than trace amounts. Mineral oil is not compatible with r134a as the refrigerant won’t circulate it. Trace amounts are fine, it will just settle to a low point in the system and remain there.

if you have a brand new system free of mineral oil, use PAG with 134a. If you system is not new and you are mixing 134a with an unknown amount of mineral oil, use POE oil.

if you are still using R12 use the Ford spec paraffin mineral oil. YN-9 which was superceeded by YN-9A (F73Z-19577-AA)
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About to start reassembly. Honestly, if you’ve taken it apart, you can likely figure out how to get it back together. It’s not overly complicated as you are just replacing the three main o-rings and the two valve plate seals.

shaft seal is a little tricky, but luckily there is a video. Pay attention to the first half of the video as this is the style in the 6P compressor

View: https://youtu.be/sh-KIjAqh-A

I will update with pics of reassembly shortly, but like I said, if you’ve made it this far you are likely able to reassemble without too much issue