Adding Air Conditioning to a 250SL

[Mpgeslak]

As part of my refurbishment of the interior of my 1967 250SL I have decided to add air conditioning as I will be bringing the car to Georgia when I leave the UK and it will be a must for summer driving.

I have read all the posts about adding Air Conditioning and from the recommendations on this forum I decided to go with Classic Auto Air.  I called them yesterday and they said they only had units for the 280SL, something about issues with the brackets and fit of the systems they found out about after they purchased Restomod Air (I think that was the name quoted).

I thus am looking for some advice:
1.  Is the 280 kit much different from a 250 kit?   Would it require much adaption to make it work in my 250?
2.  Any other recommendations?  I had seen Vintage Air quoted in the forum, but when I look online I couldn’t find kits for our cars.
3.  I have also seen posts about the kits from Buds Benz, but also read about a lot of problems with the installation
4.  I have also read about getting the right bracket for the Sanden 508 and I have seen photos of it installed, but does anyone have a picture of one out of the car so I can make sure I get the right one?  Or a good source, I read you can search on York to Sanden bracket, but when I do a few different versions come up.

Any help would be appreciated!!

[dpreston Virginia]

The Buds Benz unit works great. I have it in my 280SL and 280SE 111.
They also provide phone and email assistance when installing.
No problems with operation the 280SE unit is 10 years old.
David

[johnk]

You can get a true Sanden 508 compressor rather than a knock off from Summit racing delivered for $200. I can send you a picture of my compressor and bracket but it won't be until I am back at the barn this weekend.

[Mpgeslak]

Thanks John, that would great.

Any suggestions on how to source the rest of the parts?

[Mpgeslak]

What bothers me about the Bud's system is the use of the very large bracket.   Not sure why they don't go with an MB Sedan bracket style with the York to Sanden bracket which they sell?  Would seem to make the installation a lot easier from the posts I have read in the forum.  Also, after speaking to them, they don't use a Sanden compressor, not sure which brand they use.   

Is there a source for MB Sedan brackets that can be used instead of the larger Bud's bracket?

[Norm]

I added the Bud's Benz A/C to my 230 SL about 10 years ago but never liked the the loss of knee room for the passenger.  I finally decided to make a change for the inside unit to a Kulmeister.

Always happy with the rotary compressor and "top mount" position.  Now much better for "looks", knee room and air distribution.

Yes, there were some fitment issues with the Bud's compressor mounting bracket but a little machine work by my very capable mechanic (Helmut Holder R.I.P) and operation has always been great.

Bud's personnel helped me with new face plates for the Kulmeister unit and mentioned that they have refurbished several Fridgiking and Kulmeister units for customers.  Maybe they have something reconditioned available for sale.

Norm

[Mpgeslak]

Thanks Norm!

How tall is the Bud’s unit and how tall in your Kulmeister unit?

Also, what is your belt configuration?  Looks like your compressor has two grooves for belts but you are only using one belt?

Thanks,

Michael

[Norm]

I have three belts with the middle belt to drive the compressor. The forward belt drives the power steering and the back belt drives the fan / water pump, alternator.

The Kulmeister unit face is 2 1/2 inch "tall" but the placement of the blowers in the front of the foot wells and the housing for the condenser is more efficiently placed for passenger comfort vs. the Bud's Benz unit, in my opinion.  Plus I like the look of the period correct unit.

Be aware that the period correct dealer installations as well as the Bud's unit take up significant space.  I believe others here have discussed designing a system that uses space in the dash that, depending on what you want, may be a better answer.

Before you purchase anything, you should look at a car with A/C to see what space you will lose.

Norm

[beachbear]

I understand your question refers to A/C installation in a 250sl.

I'd like to suggest Classic Auto Air: https://www.classicautoair.com/product-category/complete-ac-systems/european-ac-systems/mercedes-ac-systems/mercedes-benz-250-sl-lhd/

A couple of years ago I bought a kit from Buds. It couldn't be installed then. It sat until I had the engine refurbished. We are working with the A/C installation now. The BudsBenz kit uses their own bracket that covers the water pump and presents clearance problems for other components like the thermostat cover and the bypass pipe. We (the mechanic and I) aren't quite sure what issues or adjusted hours Buds is working with right now, but we have not been able to get anyone on the phone and messages went unanswered. So, without any support for fitment issues forthcoming from Buds (the installation instructions are more like suggestions), I bought a bracket kit and compressor from Classic Auto Air. The bracket kit is a lot like the Mercedes sedan bracket plus other hardware such as a pulley. The pulley provided by Classic doesn't fit well with the balancer. The couple of millimeters difference means a lot for belt alignment. I anticipate we'll turn the pulley on a lathe locally to adjust the fit.

I still plan to use the blower and drier from the Buds kit. I hoped to use the compressor too, but the compressor Bud's shipped me is too long between the flanges. It's a 508 style compressor, but Classic uses a shorter SD7H13. So, that unit arrives Wednesday.

I don't predict an easy go for any A/C kit you choose, but from what I see from the two kits I have, the Classic Air kit seems better. I do prefer the blower from Buds. It angular shape doesn't match the interior styling, but I had mine covered with MB-Tex to match the interior, so there's that.

Better luck with your 250.

[doitwright]

The BudsBenz kit uses their own bracket that covers the water pump and presents clearance problems for other components like the thermostat cover and the bypass pipe.

Using a Mercedes W108 (sedan) bracket will also require a different thermostat top with a taller neck to clear the AC bracket. Based on the photos on the ClassicAutoAir.com site, their bracket looks similar to the sedan bracket. The Buds looks like a simplified version.

People who have opted for the sedan bracket agree that servicing the compressor is easier than the beast bracket used on the Frigiking which requires moving the alternator from its original location. Use of the sedan bracket became possible on SL’s when the rotary (Sanden) compressor was used in place of the larger York.

ClassicAutoAir should be informed if their crankshaft pulley does not fit properly since the photo looks like a copy of the pulley used on frigiking installations. I am not aware of anyone else who manufactures a crankshaft pulley that is needed to add AC o a non-AC car.

[Mpgeslak]

Thanks for the additional information.

I spoke to Classic Air and they are no longer selling the 250SL unit as they weren't happy with the fit of the compressor and condenser brackets.   They are still selling the 280SL units, should the fit be much different between  the models?  I am not aware that Bud's sells a different unit for 230/250/280.   I would prefer to go with the Sedan bracket but like mentioned above, the only place that sells one that looks similar to the original is Classic Air and I haven't been able to source a used one.  I am concerned about the fit with the balancer mentioned above.  This is beginning to look like a more complex project by the day!

I have managed to find a thermostat housing for my car with the longer neck so I think I have that sorted.

[beachbear]

ClassicAutoAir should be informed if their crankshaft pulley does not fit properly since the photo looks like a copy of the pulley used on frigiking installations. I am not aware of anyone else who manufactures a crankshaft pulley that is needed to add AC o a non-AC car.

I agree Frank, and I will tomorrow. But I think, surely our cars don't have such variability that the pulley supplied should fit most but not mine. Experience tells me to look closer, and I intend to with ClassicAutoAir's's assistance. Upon finding the issues (after closing hours at ClassicAutoAir) I examined installation minus the compressor and it didn't seem there could be a variation to the installation that would result in aligned pulleys. I hope for a head slapping explanation, since we'll have to locate a machine shop that has an open purpose lathe to slap a pulley into.

On my installation, the thermostat cover seems to fit so far. I looked for a longer necked cover, but didn't have enough information. What terms did you use when looking, Mpgeslak?

[Mpgeslak]

I used "Mercedes W108 W111 Thermostat Housing" and a few options on Ebay come up

[Mpgeslak]

I continue to research installing an AC unit in my 250SL, and have a couple of follow up questions:

Will a bracket from a 280SE fit on my 250SL?

What size condenser do I require for my 250SL?

As always, thanks for any advice and information!