Compressor bracket... 1980 300SD - Page 3 - PeachParts Mercedes-Benz Forum

1980sd · #31 07-05-2011, 02:45 PM

If I posted on weldingweb they would have seizures from overexposure to AWESOME!

Yea, I almost took it some where to be welded but I was worried about warpage. Believe it or not it did shift from the position of the tack welds

I had to move around to avoid too much distortion and you have to get it HOT to get decent penetration. The job really calls for a bigger machine than mine and better skill than I possess.

This is how the bracket is supposed to be used:

I just figured the single bolt would be stronger but I may look at using some welded nuts or threaded rod. A slightly shorter bolt may work as well...

Some pics:

This is it with the manifold tubes and the power steering pump in place.

I think I would be wasting my time even trying to fit the oil cooler lines

Without power steering pump:

Bench shot:

Those fittings are supposed to be everything I need to rig this stuff up. You can see how much clearance you lose with the 90 deg fittings off the compressor.

I rechecked and it looks like the oil cooler lines WILL clear. Thank God...

1980sd · #32 07-06-2011, 11:03 PM

Fooled with it a little tonight:

I got an FK head because I hoped the service valves would be accessible but I decided to put 134a manifolds on it as well. Everything clears the oil lines but plain 90 deg manifolds would allow the lines to point either direction with plenty of room. The way it is now the 134a ports prevent them from being positioned the right way. (Hi to the front/lo to the rear.) There is still room to turn them around but it would put the hi port directly under the power steering pump and I don't think I could access that port with a gauge manifold.

It's tight in there but not as tight as the pic makes it look.

I mainly did it like this so it would be easier to try out both refrigerants if I want too.

Anyway... So far so good. I need to rig up an oil cooler line bracket on one of the compressor arms that will allow enough clearance to get to the tensioning bolts.

Front view:

1980sd · #33 07-11-2011, 01:16 PM

Oil cooler lines bracket:

1980sd · #34 09-04-2011, 01:59 PM

Just in time for fall!

http://www.youtube.com/watch?v=G2XnY8lmC2o

I was manually switching the compressor.

"Band on the run" was playing on the radio...

1980sd · #35 09-22-2011, 07:46 PM

Update:

This was the old system of holding belt tension:

Seems the bolts weren't enough to keep the belt tight. It even loosened after driving about 120 miles without the compressor engaged

Jim, AKA engawork looked at it and suggested bolts to hold tension here on the bottom:

He actually suggested welding lugs on the side of the bracket with through bolts but I drilled/tapped a plate and welded it on. I need to replace the bolts with shorter ones and install lock nuts. But I think this'll solve my loose belt problem. Before it was near impossible to hold tension on the belt AND tighten the adjustment bolt...

I'm going on a 400 mile trip tomorrow and I'll test it out with the compressor off.

Wish me luck!

engatwork · #36 09-22-2011, 09:02 PM

Drilling and tapping the plate and then welding it on looks like a better way to do it.

Also, put large flat washers underneath the fastener (both ends) that goes through the adjustable side.

Looks good

.

1980sd · #37 09-24-2011, 04:53 PM

So far so good! I drove 410 miles and checked it and the belt tension is holding. Today I drove about 30 miles with the compressor engaged and all looks fine.

Thanks again for the help Jim! I never would have thought of that!

engatwork · #38 09-24-2011, 09:04 PM

Anytime Jon.

Did it maintain the under 40dF vent temps at highway speed?

1980sd · #39 09-24-2011, 09:39 PM

Quote:

Originally Posted by engatwork

Anytime Jon.

Did it maintain the under 40dF vent temps at highway speed?

It stayed right around 40dF but when I slowed down it would drop to the mid 30's

The belt looks fine but I'm wondering if it got glazed from slipping?

The tension is holding fine though. I'm also going to put the flat washers on the adjustment bolt like you suggested.

engatwork · #40 09-24-2011, 09:47 PM

Post the gauge pressures at 1500 rpm and idle. I'm wondering if the compressor is cutting out on low pressure while at speed.

How much freon did you put in it?

1980sd · #41 09-24-2011, 09:55 PM

2 lbs of 134a. I have an LED light that is illuminated when power is applied to the clutch. It has never gone off... No cycling, nothing. I have a binary switch (more for safety than any CCOT stuff) that is 10psi and 375psi. I'm relying on the evaporator switch for cycling.

engatwork · #42 09-24-2011, 09:58 PM

Put the gauges on it and post it at idle and ~1500.

1980sd · #43 10-03-2011, 04:17 PM

Ambient temp 67 F

Doors open windows down. No fan in front of the engine, just the aux fan.

Before starting the engine the gauges were 67 PSI.

I started it up and it took 15 minutes at idle for the thermostats to open. Engine temp was 80 C.

While the engine was warming up the pressures rose to 74 PSI.

Once the compressor was engaged the low side dropped to 17 PSI and the high side rose to 135 PSI.

The vent temps dropped to 35 F in less than 5 minutes.

I revved the engine to 1500 RPM and the Low side dropped to 11 PSI and the high side rose to 150 PSI.

After shutting the engine down the pressures stabilized at 55 PSI. I thought that was weird.

Any thoughts?

leathermang · #44 10-03-2011, 05:06 PM

Any thoughts ? Yes, worthless information coming from a halfway test..
Put the fan in front of the radiator like the test calls for and tell us what happens...

1980sd · #45 10-03-2011, 06:12 PM

OK. Big fan in front of mein auto. Simulate autobahn speeds...

Ambient 72F

I got 72 psi when the gauges were hooked up.

Compressor ON fan on high, doors open...

lo 15 psi high 130 psi.

It rose to 17/140 after 5 minutes of running. Temp at center vent 39 F.

1500 RPM:

Lo dropped to 10 psi and hi rose to 150 psi.

After it returned to idle the pressures stabilized at 15/140. Vent temp was 37 F.

The low pressure is getting pretty close to the low pressure shut off but it hasn't cycled that I can tell.

Better than being close to trippin' the hi pressure switch!