Changing the Air Compressor belt

[hawkeyepoole]

I didn't find any posts that said what I'm going to say, so I'll post away!

BlueDeuce and I changed the air compressor belt on my '79 AMG M35A2 today.
BlueDeuce brought the air compressor tools he bought from someone on the forums. The tool with the big cross on it for the front of the compressor pulley was fine, the one for the back was crap. It was about 1/8" to wide and was actually cut flared so that the outside of the wrench was wide than the inside. Luckily one of our volunteers in the museum is a welder, and he welded up the wrench and ground it back down to the proper size.

We had to put quite a bit of penetration oil on the pulley to get it to budge and we had to use 4 foot breaker bars to get enough leverage to begin to loosen the two halves. It squeaked and squealed and we took almost an hour to get it loose enough to get the belt off.

We then continued to loosen the pulley halves until they were separated. We then coated the threads with 90 weight oil and rejoined the halves. After a little complaining and squeaking the oil took hold and we were able to spin the two halves easily.

We then put the belt on, and with BlueDeuce holding the belt 'up' so I could screw the two halves together, we managed to get the belt up on the "V" part of the pulley, and we tightened the halves to get the belt to the proper tension. We then reinstalled the two bolts to hold the pieces in place and we were done!

While possible to do this job single-handed (double-handed actually<G>) It was definitely much easier with and extra two sets of hands. Especially when it came to properly seating the new belt.

We didn't take pictures as there are quite a few YouTube videos and pictures elsewhere you can easily find. Also, beware some of the compressor wrench tools being sold. If they're made on a CnC machine they'll likely be better than some others. I don't know who made what we used, but they weren't quite right until we modified them.

 

[comdiver]

The ones I sell are all cut on CNC equipment. They are made a little loose to accoumt for different castings and paint build up. I also designed another wrench that is a open end for the other side. The "other guy" bought a set of mine, took the designs, now is making and selling them. He is cheaper than me, but I incluide shipping and from what you said he knows what his are worth! Anybody who needs help changing the belts PM me. I don't care where you purchased your wrenches, I will walk you through it. If your close to Buffalo drive over and we can change them at my place with my tools.

 

[Recovry4x4]

Yes, they can be a .......challenge to say the least. I got my wrench from John Souza in CA a decade or so back. He made the handle substancially longer and thicker. The difference between his wrench and the factory size wrench is well noticed on a stuck pulley.

 

[rronning84]

I didn't know there were special wrenches for this. I used a pipe wrench and a Cresent to do mine and cussed the whole time.

 

[lawdog1623]

i actually used a modified wrench i had for rifle manufacturing. It worked like a charm and ill definitely use it again. However, i did have a difficult time getting the back side of the pulley off. I ended up purchasing a real good heavy duty pulley puller / brake caliper remover that presses against the compressor output shaft. This thing was expensive but it popped it right off with little effort. I figured it was a good investment seeing as how i have multiple trucks now.

 

[Heavysteven]

I made a video if any one does not know what the wrench looks like. It's NOS so I have no opition on who's is better.

[media]http://www.youtube.com/watch?v=gw7uW8qJ9NU&feature=youtube_gdata_player[/media]

 

[Radiogeek99]

I just did this on mine a couple of weeks ago. I also needed to soak everything down and put long bars on the compressor wrench to loosen the pulley. Although my wrench for the back was too small and I had to adjust it bigger. I had a hard time trying to get the new belt in place and had to draft an extra set of hands. Much easier putting the new belt on with help!

 

[Katahdin]

Was just wondering if everyone's belt/compressor makes a little noise when its building pressure. I tightened the belt to the prescribed measure of deflection when I had the radiator off, but I've had to tighten it some more to quiet it down some. I'm using a NAPA belt.

 

[hawkeyepoole]

I made a video if any one does not know what the wrench looks like. It's NOS so I have no opition on who's is better.

[media]http://www.youtube.com/watch?v=gw7uW8qJ9NU&feature=youtube_gdata_player[/media]

That's a great video. It's actually why I didn't shoot my own. I love this place!

 

[cliffreckley]

I'd appreciate any info/pic's etc to help get this changed. Last thing I got to do before a day long road trip to Boyce Equip in Ogden for lots of parts. I figure if I know what way things turn and come off I could get it off. Will buy a tool from you if it comes to that. Thanks, Cliff in NV.

 

[Heavysteven]

https://m.youtube.com/watch?v=gw7uW8qJ9NU

 

[TsgtB]

You may have to re-tighten it, the belt I put on stretched some.
I didn't have the proper tool, but after loosening the two bolts, I was shocked that the halves turned easily (after being canned since 92)
and a little PB blaster before I ever touched it.
I was able to hold the belt up and spin it enough to get tension on the belt, spun the engine and let it tighten itself and tightened the bolts...

 

[onemanarmy]

So, you just loosen those 2 bolts and then turn the pulley to loosen it enough to remove the belt? which way do you turn to loosen?

I was looking at the wrench sets on Electronics Bay, are both necessary?

 

[gimpyrobb]

Yes, just loosen and turn. If you have big wrenches, no both are not needed. If you don't have big wrenches, it is handy to have both!

 

[Floridianson]

And to tighten the belt just start the truck with jam bolts loose. Tighten jam bolts go have FUN!
For those who are not real fast with a wrench shut down motor before tighten up the jam bolts please.

 

[hawkeyepoole]

Yeah, I'm not so good on spinning the engine to tighten the pulley. Get that bit + shaped wrench or borrow from a friend and I used a big vice grip to hold the back of the pulley. You don't want to over tighten the belt. I allow about 1/2" of deflection when I push with one hand on the belt.

 

[Floridianson]

You don't have to be good. That is just the way we do it.

 

[winfred]

doused mine with soapy water so the belt would slip as i spun the pulley to tighten a loose belt, just had water pump pliers to work with

 

[Floridianson]

You can lead a horse to water.

 

[Z71]

I remember when I did this job for the first time, I had already had the special wrench, but the handle was too short so i could not loosen the pulley hub. I slipped a 3 ft pipe over the end of the wrench handle and that did it. As for the other (nut) wrench, I just used a large open end wrench of the right size, which had a lot better leverage than the stubby handle special wrench they offer.