Sanden compressor question - PeachParts Mercedes-Benz Forum

TheDon · #1 06-19-2014, 10:59 AM

Installed a sanden and charged it. Worked great and then two weeks later the belt is squealing and making noises like the R4 was prior to me nuking that thing.

I know the sanden has an internal oil reservoir. But I charged the system with oil and then freon. The charge was an 8 oz can and 2.2lbs- ish of 134A. Pressures looked fine according to Colin (we used his tools).

So is it possible I overcharged the system with oil? My Benz guru suspects either a blocked condenser or overcharged with oil.

Thoughts?

BillGrissom · #2 06-19-2014, 03:49 PM

Sounds like about the right amount of oil. Too much oil will not directly jam the compressor. Its downside is to reduce heat transfer in the evaporator and condenser, which can cause high-side pressure to rise, which then fights the compressor. You need to read the operating pressures. I bought the Harbor Freight gage set for ~$20 on sale a few years ago, and use it all the time on all my cars, but you can get just a high-side gage cheap.

What type oil did you use? A downside of PAG is that I understand it forms corrosive acids if it ever gets moisture. That can happen if you lose refrigerant and don't take care of it right away. You also must buy the correct viscosity. I read that PAO 68 is the best oil to use today. Works with any refrigerants, stays put in the compressor better, doesn't absorb moisture, and works for any required viscosity. Can buy on ebay. I bought Duracool's version.

I hope you didn't start with a dry compressor and then just add a can of "oil recharge". Best to pour the oil directly in the Sanden fill port, per their manual (can down-load on-line). Try spinning the compressor by hand (engine off, key in your pocket). Spin the inner part (not pulley w/ V-belt). It should spin fairly easily and you shouldn't feel a rough bearing or dragging pistons. If really determined, remove the refrigerant hoses and verify that you feel pressure build up on your thumb over the outlet and suction on the inlet, but that means dumping your refrigerant (illegal w/ R-134A, OK w/ my Duracool).

eatont9999 · #3 06-19-2014, 05:44 PM

Quote:

Originally Posted by TheDon

Installed a sanden and charged it. Worked great and then two weeks later the belt is squealing and making noises like the R4 was prior to me nuking that thing.

I know the sanden has an internal oil reservoir. But I charged the system with oil and then freon. The charge was an 8 oz can and 2.2lbs- ish of 134A. Pressures looked fine according to Colin (we used his tools).

So is it possible I overcharged the system with oil? My Benz guru suspects either a blocked condenser or overcharged with oil.

Thoughts?

Mine did the exact same thing. I also have exactly 8oz of oil in my system.

I tightened the belt and the squeeling went away. It may not seem like it but the belt may have stretched and is slipping.

TheDon · #4 06-19-2014, 07:43 PM

I cranked the belt adjustment as tight as it would go and still the same issue.

TheDon · #5 06-19-2014, 07:58 PM

What the hell. The adjustment bolt snapped off the adjuster. I removed it and now the threads for the adjuster are fubar'd.

I am so over Dealing with the AC on this damn car.

TheDon · #6 06-19-2014, 08:12 PM

Quote:

Originally Posted by BillGrissom

Sounds like about the right amount of oil. Too much oil will not directly jam the compressor. Its downside is to reduce heat transfer in the evaporator and condenser, which can cause high-side pressure to rise, which then fights the compressor. You need to read the operating pressures. I bought the Harbor Freight gage set for ~$20 on sale a few years ago, and use it all the time on all my cars, but you can get just a high-side gage cheap.

What type oil did you use? A downside of PAG is that I understand it forms corrosive acids if it ever gets moisture. That can happen if you lose refrigerant and don't take care of it right away. You also must buy the correct viscosity. I read that PAO 68 is the best oil to use today. Works with any refrigerants, stays put in the compressor better, doesn't absorb moisture, and works for any required viscosity. Can buy on ebay. I bought Duracool's version.

I hope you didn't start with a dry compressor and then just add a can of "oil recharge". Best to pour the oil directly in the Sanden fill port, per their manual (can down-load on-line). Try spinning the compressor by hand (engine off, key in your pocket). Spin the inner part (not pulley w/ V-belt). It should spin fairly easily and you shouldn't feel a rough bearing or dragging pistons. If really determined, remove the refrigerant hoses and verify that you feel pressure build up on your thumb over the outlet and suction on the inlet, but that means dumping your refrigerant (illegal w/ R-134A, OK w/ my Duracool).

I'm tempted to just have a massive accidental leak and charge it with ES12 since I have 7 cans of it.

The compressor shipped with oil in it and I spun if to lube it. The adjuster bolt snapped and destroyed the adjuster on my Sanden conversion kit. I'm incredibly pissed off right now

TheDon · #7 06-20-2014, 09:28 AM

RollGuy is sending me a replacement adjuster and bolt. Hopefully the issue was just a loose belt. The R4 worked fine when I had it in and the pressures for the sanden were OK. A blockage would have shown itself at that time, yes?

ROLLGUY · #8 06-20-2014, 10:09 AM

The compressor is shipped with about 6 oz of oil, and 8 oz is what the total oil should be. If you added an additional 8 oz to the system, you probably have 6 oz too much. That alone might have caused the belt to slip, as the compressor is not made to compress liquid (refrigerant or oil). I had a belt slipping problem on one of my cars, and the compressor belt was tight enough to play a tune on, and still the squealing was there. It was suggested that my alternator was loose, and that was the source of the noise. I tested this by unplugging the alternator wiring, and the noise went away. I tightened the alternator, and now the belt does not squeal. I have learned not to blame the A/C compressor for belt noises until thoroughly investigating the cause.

pawoSD · #9 06-20-2014, 10:16 AM

It seems like the alt belts on the 617 are more likely to stretch as they are a lot longer than the A/C belt and always under more load....I had to tighten them a couple times on my 300SD after replacing them to keep the proper tension or they'd squeal when the afterglow was running and loading the alternator....ever since the second adjustment it has been fine, must have "settled in". Make sure not to go too tight though, don't want that crank pulley coming off

Strangely I've never had the issue on my 420....and that has longer v-belts and can go to higher rpms....

TheDon · #10 06-20-2014, 11:10 AM

RollGuy is sending me a replacement adjuster and bolt. Hopefully the issue was just a loose belt. The R4 worked fine when I had it in and the pressures for the sanden were OK. A blockage would have shown itself at that time, yes?

TheDon · #11 06-20-2014, 11:11 AM

Quote:

Originally Posted by pawoSD

It seems like the alt belts on the 617 are more likely to stretch as they are a lot longer than the A/C belt and always under more load....I had to tighten them a couple times on my 300SD after replacing them to keep the proper tension or they'd squeal when the afterglow was running and loading the alternator....ever since the second adjustment it has been fine, must have "settled in". Make sure not to go too tight though, don't want that crank pulley coming off

Strangely I've never had the issue on my 420....and that has longer v-belts and can go to higher rpms....

Noise only happens when the AC clutch is engaged. Also the belt that shipped with the SANDEN kit is almost impossible remove. I have the compressor adjusted all of the way to the block and I can't slip it over.

TheDon · #12 06-20-2014, 11:32 AM

Quote:

Originally Posted by pawoSD

It seems like the alt belts on the 617 are more likely to stretch as they are a lot longer than the A/C belt and always under more load....I had to tighten them a couple times on my 300SD after replacing them to keep the proper tension or they'd squeal when the afterglow was running and loading the alternator....ever since the second adjustment it has been fine, must have "settled in". Make sure not to go too tight though, don't want that crank pulley coming off

Strangely I've never had the issue on my 420....and that has longer v-belts and can go to higher rpms....

Noise only happens when the AC clutch is engaged. Also the belt that shipped with the SANDEN kit is almost impossible remove. I have the compressor adjusted all of the way to the block and I can't slip it over.

pawoSD · #13 06-20-2014, 11:42 AM

Quote:

Originally Posted by TheDon

Noise only happens when the AC clutch is engaged. Also the belt that shipped with the SANDEN kit is almost impossible remove. I have the compressor adjusted all of the way to the block and I can't slip it over.

Even with a flate blade screwdriver for guidance?

ROLLGUY · #14 06-20-2014, 02:10 PM

Quote:

Originally Posted by TheDon

Noise only happens when the AC clutch is engaged. Also the belt that shipped with the SANDEN kit is almost impossible remove. I have the compressor adjusted all of the way to the block and I can't slip it over.

That is exactly what I experienced on mine until I removed the plug from the back of the alternator. Removing the alternator from the system killed the squealing belt. After tightening the alternator and connecting the wiring, the noise was no longer there. As far as the belt length, you have to "help" it on. I usually get the belt on as far as it will go, and then just bump the starter. Usually the belt goes on the first time. Also, the exact length of belts from different manufacturers varies, and I don't want the belt to be too long and the comp hit the frame or run out of adjustment. I will try a little longer belt when I order another batch....Rich

TheDon · #15 06-20-2014, 03:23 PM

I got it on, its the removing part that looks like its going to be fun. When I have to get to the alternator belt I am honestly just going to cut the belt off.

I will do the alternator test, again. But I swear its the AC compressor making the noise with the clutch engaged. I am going to be overly pissed if I have to evac, clean, and charge the system again.I am completely fed up with dealing with AC issues. I have never had a car that fought me ever damn step of the way. I just want it to work, I love the sanden kit, its incredibly well built and when it worked cooled like a champ.

Quote:

Originally Posted by pawoSD

Even with a flate blade screwdriver for guidance?

to get it on I bumped the engine over and it slid on like butter.