A/C Compressor Vibrates

[FeFranco]

Any possibility of taking a picture of that spacer for us to see? And any other suspect parts?

[bcomo]

More on the AC Belt Vibration

I wanted to find out if the Fan and spacer were a factor in the wicked AC belt vibration.

I removed the Fan and spacer, and used short bolts to keep the AC and Gen Pulleys attached with the belts.

The vibration in the AC belt was exactly the same -- bad at idle, and REALLY bad with the AC engaged with more load on the belt.

This means that the problem exsists between two pulleys and a belt between them -- sounds simple -- but this has turned out to be a tough geometry problem.

Without the fan and spacer, I was able to run a straight edge between the pulleys, and find that they are not in perfect alignment. The compressor pulley is at a slight inward angle to the fan AC pulley.

Since the rotation of the belt is toward the AC compressor, this makes the belt want to ride up against the AC compressor pulley and jump up against the high side of the pulley.

At this point, I don't see much in the way of pulley adjustments to align the belts.

I'm going to try shims under the compressor to move the top of the compressor pulley in line with the AC fan pulley. That may not work.

Anyone have any other ideas?

[ncbird]

Bart, first I assume you bolted the fan pulley to the water pump correct? That said they way you describe it the belt runs toward the block from the fan pulley meaning the compressor pulley is closer to the block. I dont know how the bracket for the compressor mounts but is it possible it had spacers between the bracket and the Head/block that have been omitted accidently? Can you post pictures of the compressor and bracket? Grant

[tbird430]

My AC compressor bracket bolted flush to the block without spacers or washers....

[bcomo]

Grant -- Yes, both the Gen and AC Fan pulleys were bolted to the water pump for this test. Missing washers was a possibility that I thought of, but I don't remember any being there.

Jon -- On mine, first there is the PS bracket on the block, then the AC bracket is in front of that with bolts (no spacers or washers between them) directly to the block. Is that what you have??

Thanks

[tbird430]

Bart I haven't gotten my power steering pump nor A/C compressor back on yet. I did get you those pics of the waterpump pulley & my A/C compressor.

Front veiw:



Rear veiw:



A/C Compressor:

[bcomo]

Thanks Jon.

It looks like my AC fan pulley is the same size.

My compressor is slightly different than yours.

Maybe you could snap a photo of the AC and PS brackets -- if you get a chance.

[tbird430]

Will do. (I now see u got the pics)


-Jon

[tbird430]

More pics Bart. This is the A/C Clutch pulley 6.75", just like my waterpump pulley:



My Power Steering Brkt.





My A/C Compressor brkt.





***Note the smaller bracket rear ear has broken off of my A/C compressor brkt. What is left is being shown here held with pliers. It simply bolted to the main A/C compressor bracket and then the lower front head bolt originally***

[bcomo]

Thanks Jon.

My compressor pulley is exactly the same, even down to the same 3 lobe clutch center.

I don't have that "ear" on the AC bracket at all. The threaded hole is there, but I don't know if that does much to support the bracket. Are you going to try to make a new one, or just leave it off?

By the way, I found it impossible to put in one of the bolts underneath that mount the compressor to the bracket. There is no room for hands, or a tool, to tighten it even if you get it in from underneath. Let me know if you figure a way to get that done when you mount the compressor.

[tbird430]

I will try and find one, then probably end up having to leave it off as well....

[tbird430]

Here are the measurements of my A/C Compressor Bart:








The clutch:

[bcomo]

Thanks Jon.

I see that our compressors are the same. So, that's not an issue.

I also had the R-12 level checked AGAIN, and it was exactly what the manual said that it sould be. So, excessive head pressure is not an issue.

I went to Carlisle Auto Air in San Antonio. They are the people who install the "Classic Auto Air" systems. I talked with them about the excessive belt vibration at Idle with AC on.

They told me that the York compressor was a big unit that was also used on large trucks of the era. They said that it needed to have a REALLY tight belt to eliminate the belt vibration because of the weight of the AC pulley being turned.

I asked them what they could do if I brought the car in for them to look at. They said -- Tighten the belt more.

When you mount your Compressor, please let me know how you get the "mystery bolt" on there. That would be the bolt on the inside, closest to the engine block.

Still need someone to do a comparative AC belt check sometime.

[tbird430]

We installed that bolt 1st and left it finger tight. We hope to be able to tighten it after we get the a/c compressor & the other 3 bolts tight. We are breaking for lunch right now.

-Jon

[JohnG]

Two quick thoughts (from someone who never worked on an AC of any kind):

1) I would see if I could find another pulley at a salvage place and try it, in the thought that the one I had was particularly out of balance

2) I would see if I could find a machine shop that specialized in balancing and let them see what they thought of it and might do with it

I would not want to tighten the **** out of the belt for fear of the stress it would put on something like the water pump, unless it does not go around anything fragile.

John

AC Less 58 Hardtop