Chillin' Louie (Part III: The Compressor, Bracket, and Injection Belt Cover)

In the previous piece, I installed the tii-specific a/c crankshaft hub that has a compressor pulley behind the cogged gear that runs the injection pump, and explained that what that means is that the next steps are to:

1. Install the compressor, bracket and belt, and correct any belt alignment or tension issues.
2. Modify the notches for the belt in the plastic lower timing belt cover if they already exist, and create them if they don't.
3. Then put the injection belt back on and button things up.

It was now time to do those things.

Compressor

The go-to compressor for a retrofit or rejuvenation is the Sanden 508 or one of its infinite Chinese-made clones. I've generally bought whatever's available cheaply (as low as $80) on eBay from vendors with high feedback numbers. After installing perhaps ten of these, have yet to have a failure, but if you want to buy something with more provenance and less risk, you can buy on Amazon where you can look at actual reviews, or buy from one of the online a/c specialty shops like Vintage Air, Old Air Products, Nostalgic Air, Restomod Air, etc, or online race/hotrod shops like Summit or Jegs.

There are, however, a few things you need to know before you click and buy.

First, be aware that, even though many people call these "rotary compressors," they're not. They're piston compressors in a paint can-style compact form factor. Not that there's anything wrong with that. I try to call them "rotary-style" just to be consistent and accurate. In the photo below, you can see the five pistons (the "5" in the "508").

The pistons inside a "rotary-style" Sanden 508 compressor.

Second, the 508 and its clones come with either a grooved serpentine belt pulley or two V-belt pulleys. Unless you have some modern Honda engine in your 2002 with serpentine belt accessories on it, you want V-belt pulleys.

Third, as I say in my a/c book, retrofit or rejuvenation is an opportunity to do away with as many of the old leak-prone flare fittings as possible in favor of modern o-ring fittings. The old York compressors had, I believe, two #10 flares, but almost any modern compressor you'll buy has a #10 and a #8 o-ring fitting, and that's a good thing. The point is that you don't want to accidentally buy a compressor with flare fittings on it. Note, however, that the round flat plate on the back of the compressor (referred to as the "back head") that has the hose fittings on it can be easily replaced, so if you have an old working Sanden 508 with flare fittings, you can simply buy a Sanden head with o-ring fittings on it. I did this a few years back when I resurrected Bertha, the 2002 I owned nearly 30 years ago whose compressor I'd already updated.

Bertha's Sanden compressor with the new o-ring head on it.

Fourth, you need to be aware of where you're going to locate the charging fittings to hook the manifold gauges to. Some back heads have Schraeder-style thread-on charging fittings directly on them right below the hose fittings (in the photo above, you can see the holes for those fittings). Some don't. Although these are R12-style charging fittings, you can still use them with R134a, and it makes for a cleaner installation, but a) they're difficult to reach, and b) they always blow a surprising amount of refrigerant when you're disconnecting the manifold gauge hoses; the snap-fit R134a fittings work much better, and that's what I recommend using.

So, procure a compressor with the Sanden 508 form factor, a V-belt pulley, o-ring fittings, and charging fitting configuration you're aware of (that is, if you're relying on the screw-on compressor charging fittings as being the only charging fittings on the car, make sure it has them).

For this a/c retrofit into Louie, I actually had two used compressors I could take advantage of. The first was the original Sanden 508 that was part of the used full-up Clardy system I bought at The Vintage. Yes, the compressor had flare fittings on the back head, but I could replace it with an o-ring head for thirty bucks. The freewheeling bearing on the pulley (the one it runs on until the compressor clutch engages) was noisy, but that's a $13 part, easily changed (see this piece I recently wrote for Hagerty). I liked the idea of reusing the original Clardy Sanden compressor. Unfortunately, when I test-fit it to the bracket, there was a lot of play. Upon examination, it turned out that one of the pivot bolt holes had worn itself into an oval. I elected not to use it.

The elongated bolt hole in the original Sanden 508 that came with the Clardy system.

The other option was that I still had the Japanese-made Seltec compressor I'd originally installed in my 1973 E9 3.0CSi in 1999. I'd replaced it a few years ago as part of a full refresh. It's a long story, but I believed the compressor to be fine. I thought "Why do I still have this thing kicking around my basement if I'm not going to reuse it now?" So I did.

The original Sanden 508 (left) and the Seltec that was in my E9 (right).

You'll notice that, in the image above, the original Sanden 508 and the Seltec have two important differences. The first is that the ports on the Seltec are upright, whereas the ones on the Sanden are more V-oriented. The second is that the clutch on the front of the Seltec sticks out further. Both of things will come into play in subsequent installments.

Bracket

As I said in the first installment, of the three dealer-installed 2002 a/c systems, the Clardy system was the only one that had a Sanden rotary-style compressor. It also came with a Sanden-specific bracket to mount the compressor to the block. I assume that Clardy bought the bracket from someone else, but I don't know. The bracket was nice in that it got away from the big messy York bracket, but its downside was that it used rubber vibration isolation bushings with metal dowels through their center. As the rubber bushings aged, they degraded, causing the entire bracket to cock and throwing the compressor pulley out of alignment with the crank pulley. 

When I put a Sanden compressor in Bertha, my '75 2002, in the mid-1980s, I used this same bracket and its rubber bushings, as it was what was available in the aftermarket. When I bought Bertha back and resurrected the car a few years ago, for both money-saving and originality reasons, I wanted to re-use the same compressor and bracket. I had two full sets of rubber bushings (the ones that were originally on the bracket and the ones that came with the full-up Clardy system), and from them I selected the best five pairs, but it was only a matter of days before the bracket and compressor cocked so badly that the compressor pulley began hitting the sway bar. I pulled the bracket out and replaced it with a "hobiedave bracket," the one Dave Donohoe sells here on the FAQ. Dave says that his bracket is a near-copy of the Clardy bracket except that instead of the big holes for the rubber bushings, he uses small holes through which the bolts directly go. In the photo below, the original Clardy bracket with some of its rubber bushings is shown on the right, the hobiedave bracket on the left.

Hobiedave bracket (left) and original Clardy Sanden bracket (right)

For many years, if you wanted to bolt a Sanden 508-style compressor to a 2002 M10 block, the hobiedave bracket was the only game in town. I've used it in about half a dozen cars and have had no problems with it. Now, however, there are several other options. Blunttech's (Steve Peterson's) bracket is click-and-buy here. I've never used it, but it looks like, as the Brits say, a nice piece of kit. I believe that the other two main vendors of 2002-specific a/c systems, ICE AC and DTech, also have compressor brackets, but I'm not certain they're click-and-buy.

If you still have a York compressor on your car and are trying to save money, you can buy a bracket adapter (a bracket that mounts to the original York bracket), but they're generally to be avoided, as they add weight and opportunities for misalignment and vibration. Besides, as I said, the original York bracket wrapped around the front of the water pump, requiring you to remove it if the water pump has to be changed. You really want it the f*ck out of your car.

Original York bracket with arrows showing how the bracket appropriates the two lower water pump bolts for support.

For the a/c installation into Louie, I was trying to save money wherever I could, so I wondered if there was an off-the-shelf metal insert that I could use to fill the holes in the original Clardy bracket. I took the bracket to my local Ace Hardware store, and lo and behold, found that 3/8-inch I.D. x 3/4-inch O.D. x 1/4-inch long metal inserts fit so perfectly that, although I planned to epoxy them in place, I never did, as simply using big washers on the bolts appeared to hold the bracket completely rigid. The same size inserts are available on eBay here.  I did have to drill out one, the one at the lower left where the big bolt with the 17mm head goes through the engine mount.

Original Clardy Sanden bracket with 3/8 x 3/4 x 1/4 metal inserts eliminating the rubber bushings

The insert is missing in the center because there's a round boss in the block at that spot, and apparently, on Louie's block, it wasn't drilled and tapped. This was interesting, as Louie originally had the non-a/c front sway bar on it that didn't jut out far enough to ever have cleared a compressor (see this post). So apparently some of these cars were less a/c-ready than others. Maybe none of the blocks have this boss tapped. It looks like this location isn't used by the hobiedave bracket anyway.

The untapped boss on my engine block.

I had no confidence that I could drill and tap into the block accurately enough for the holes to line up, so I just left it alone. I did run a tap through the threads on the other holes in the block to clean them up, as they were pretty rusty.

Running a tap to clean the threads

Then I mounted the bracket and inserts using big flat washers to capture the inserts in place.

The Clardy Sanden bracket and its inserts all mounted up.

Then on went the Seltec compressor with the usual assortment of fasteners. There were no alignment issues. Sorry for the fuzzy photo.

Seltec compressor in place

Then the injection belt went back on. Sorry I forgot to take a photo, but you can see what it looks like, and how it "captures" the compressor belt, in the photo above with the arrows pointing to the York bracket using the two lower water pump bolts.

Slotting the Timing Belt Cover

With the compressor and belt mounted, the next step was to see how the plastic lower timing belt cover needed to be slotted in order to let the compressor belt pass through it. The Behr 2002 a/c installation manual has this template in it for where to cut the cover:

Template for cutting the lower plastic timing belt cover from the Behr installation manual

To my surprise, though, when I actually looked at the plastic lower timing belt cover, I saw that it was easier than that.

The mating face of the plastic lower timing belt cover has two slightly raised tabs that slide into notched indentations in the engine's aluminum lower timing chain cover. Forgive me for not having taken more photos of this on Louie. Here's a photo of a spare lower timing chain cover kicking around in my parts closet with arrows pointing to the notches.

Lower timing chain cover with arrows showing the stock notches

Here is one of the tabs on the plastic cover, with Wite-Out to highlight the edges. 

Stock plastic tabs on the plastic lower injection belt cover.

It's actually kind of odd that these tabs and notches are there. Yes they help align the plastic and aluminum covers, but there are four bolts that do that, so the tabs and notches seem superfluous. But if you lay the Behr template on either the plastic lower cover or the aluminum one, either by choice or by chance, the "cut out this section" sections align almost perfectly with the tabs and slots. At least the one on the top did; the one on the bottom was much larger in the template. But with my compressor belt already installed, it sure looked to me like all I needed to do was turn the tabs in the plastic cover into slots and the belt would pass through them.

And I did. And it did.

The lower plastic injection belt cover notched to receive the compressor belt

And installed

When I did this nearly ten years ago with Kugel, I had to significantly elongate the notches in both the plastic and metal covers. I don't know what's different about the belt angle on this Seltec compressor as opposed to the Sanden 508 clone I used ten years ago. It's a bit of a mystery to me. But I'm grateful for it, as it made the installation easier than I expected.

Oil

One other quick note: Before I mounted the compressor, I filled it with a little over 4 ounces of ester oil. There's a long discussion on refrigerant oil in my book. R12 systems originally used mineral oil, but it's not compatible with R134a. Nearly all R134a systems use polyalklyne glycol (PAG) oil. However, ester oil is compatible with both R12 and R134a, and as such is sometimes recommended for retrofit applications. I sometimes use it if I think there's a chance the R134a conversion might not get the car cold enough and I might need to go back to R12. This was the case with my E9 3.0CSi. As such, the Seltec compressor originally had ester oil in it. I stayed with ester oil largely for that reason.

That was a lot!

Next installment: The condenser and fan.

--Rob

(My a/c book Just Needs a Recharge: The Hack Mechanic Guide to Vintage Air Conditioning can be purchased here on Amazon, or personally-inscribed copies of it and my other books can be purchased directly from me here.)