Air conditioning O Rings

[markw996]

Having searched for the last few hours I was surprised that I was unable to find an exhaustive list of the number of O Rings used in the Esprit air conditioning system, and their respective locations on the car.

 

I don't have any experience of air conditioning, but I don't think my car has ever been regassed in 19 years so I want to know where the O Rings are so I can replace them with the new HNBR type as required, before attempting to charge the system to see if any of it still works.

 

Is this information available anywhere?

 

Also, are there any common leak areas other than the O Rings?

[markw996]

EDIT:

Upon studying the parts diagrams I can only actually see 4 O Rings in the AC system

(2 on Condenser, 2 on Compressor).

 

It seems that my idea that there could be about 10 or 20 O Rings (tucked away and all leaking) was unfounded!

Edited September 7, 2013 by markw996

[internets]

There are 2 used on drier and on the expansion valve too.

[markw996]

Thanks, The drier ones don't appear on the parts diagram, and I missed the one on the expansion valve.

At least I have an idea where to look for leaks now.

[internets]

If your going to open the system you want to replace the drier and maybe expansion valve, on another thread there is part numbers or if you get stuck pm me and ill dig them out

(null)

[markw996]

Thanks, I've been reading other threads and am watching a suitable BMW E21 expansion valve on eBay, as for

the drier I am just waiting for the dealer who supplied me the car to get it into stock and post it out to me FOC.

[internets]

Try eBay auction #110933966356

Same guy I brought mine from!

[markw996]

Rather than start another new thread I thought I'd ask the knowledgeable people on here whether or not they think I have the correct AC connectors for my Esprits Sanden AC compressor?

 

When connected and disconnected I get a faint hiss, but my gauges read zero (with engine running and AC switched to on). I should add that my AC doesn't currently work, and the entire system is quite possibly completely empty of refrigerant.

 

I have linked a few photos of my compressor, the connectors, and a few others. There were covers over the compressor SUC & DIS connections which are not shown in the photos.

 

My main question I guess is really: Do my R-12 connectors press in the Schrader valves correctly?

 

   

 

  

 

   

Edited September 11, 2013 by markw996

[internets]

The hi / lo side connection ports are found under the oil sump on the hoses near where they run along the chassis to the front, well on R134a cars so would guess R12 cars are the same. So you will need to get the car on a lift or axle stands!

 

Edited September 11, 2013 by internets

[markw996]

I could be wrong (and usually am!) but I was under the impression that on R12 cars the connector underneath was a low side port, and was just an extra in addition to the one on the rear of the compressor?

[rizla603104]

I think that you will have the radiator assembly that is the A/C and charge cooler in one - not the two smaller radiators. I understand that a lot of the time it is that component that fails - in which case it is a good idea to replace the radiator at the same time as it is a complete faff that you wouldn't want to repeat in a hurry.

[markw996]

I think that you will have the radiator assembly that is the A/C and charge cooler in one - not the two smaller radiators. I understand that a lot of the time it is that component that fails - in which case it is a good idea to replace the radiator at the same time as it is a complete faff that you wouldn't want to repeat in a hurry.

 

I'm fairly sure that I do have the single chargecooler / AC setup, but I'm a bit reluctant to change it as it looks fairly new.

 

I have done a lot of research and am now pretty sure I have the correct connections as the brass rectangular piece in the middle of my hoses seems to be a valve core depressor.

 

Before I go much further, and as I seem to have no gas in the system I will do the following:

 

1) Replace all 4 Schrader valves for piece of mind

2) Pull a vacuum using the pump I won on eBay and will be collecting tonight

 

Fix any obvious leaks until it holds a vacuum then:

 

3) Have a specialist flush any muck out of the system and charge it with Nitrogen to test for leaks 

4) Replace the receiver / dryer, maybe the expansion valve, and gas/oil/dye it up myself

5) Enjoy my nice cold AC

 

I'll keep my fingers crossed it all happens in this order, and I don't have any unforeseen issues.....

[fjmuurling]

The SD 508 Sanden Compressor (original made for R12) has the testconnectors on the back hence no need for testconnectors on the HP /LP Hoses.

Later Compressors (SD5H14 made for R134a) had no backplate test connectors, so they were put on the hoses.

Are you going to put in R12?? or something else??

[markw996]

As far as I'm aware you can't use R12 any more for legal reasons... so I better not answer that

[fjmuurling]

Yep that is true. Hoses, drier, compressor, oil and expansion valve which are made for r12 are not (well) suited for the use of r134a and need to be replaced / renewed. The r12 molecules are bigger than the r134a ones. Also the operating pressures for r134a are different (higher). There is a document by sanden for changing over from r12 to r134a.

[Loose Cannon]

Hi All

I would like to replace the inlet and outlet O-rings going into my Sanden compressor before closing up the system again. Can anyone answer a couple of queries?

• Is there anything special about aircon O-rings (resistance to particular chemicals etc) or can I use common ones? The only thing that makes me think there may be a difference is the originals are bright green.
• Does anyone have a size for the larger (female) connector? They are both intact, and not impossibly flat, but not nice and plump if you know what I mean so hard to tell exact diameters. I can get a caliper on the smaller male
• Also as the system has been open a while I see a recommendation to change thei "expansion valve". I can find the BMW part on Ebay but where is the valve in the system and how hard is it to get to?

 

 

[910Esprit]

Yes - HNBR.  essential for R34

Probably #10 7/8" If you mean from the compressor

No way I'd change the expansion valve unless I had to.   It will be a nightmare.....  (under left dash AC unit)

Edited October 6, 2016 by 910Esprit

[Loose Cannon]

Thankyou. I bought a box of O rings from a UK seller, allegedly HNBR but when they arrived they were made in China out of "green rubber" according to the box!

 

Actually had a nightmare with the compressor, which made the O ring thing look piffling 0 seems the inlet outlet fittings have been overtorqued from the factory and the the casting threads came off still inside the big nut . Got the thread remians out with a dremel fitting which looked more applicable to dentists, but the head casting is borked.

 

[Chillidoggy]

As was mine. I bought a new compressor.

[Loose Cannon]

I still can't believe how I manage to miss this fact despite staring at the bloody thing on a stand the past 8 months.

 

And here was me worring about bloody O-rings. At least th new one looks nicer, shame it hasn't got a seat to work on.

The rear castings that have the ports on appear to be available in the states (natch) but add on shipping and I reckon it'll be over £60. One thing which makes it different from the few I found for sale was the peculiar valve looking thingy offset from the centre. What does this do and can it be tapped into a casting without it?

 

So dilemma; Do you repair an 19 year old compressor even when it worked perfectly prior? £300 is still a lot more than 60.

[Chillidoggy]

If you change the head casting, and it still works, then you'll be in £240 in hand. If not, then you'll be £360 down. Pays your money, takes your choice. I was advised to change my compressor due to its age (albeit by the guy that supplied it), and if the system has had any major component change, then it's highly recommended to change the filter/drier, too. I don't know what that sticky-out bit is on your compressor, I don't think mine had that on it but will check later. Another thing you might want to consider is buying an alternative to a Sanden compressor from the US, as you may well find a much cheaper one.

How are your condensers? Mine were utterly knackered.

 

[Chillidoggy]

Just checked, and the original compressor has the same sticky-out bit. My new one doesn't.

[910Esprit]

My be worth a punt?   Appear to be a couple of Sanden R134 heads there.

http://www.ebay.co.uk/itm/SCRAP-AIR-CONDITIONING-COMPRESSORS-SANDEN-MASSEY-JCB-NEW-HOLLAND-CLAAS-/391580867077?hash=item5b2c09da05:g:Q7YAAOSwzJ5XZRSl

[Loose Cannon]

Bollocks, missed your post Steve (must remember to click use the "notify replies" button!) . So much for my Ebay search for "Sanden", it didn't bring that lot up! Middle two look dead ringers too, oh well.

A new head casting on its way from US, only £30 posted with all the gaskets so fingers crossed it lands soon.

Ian, none of the replacements have the sticky out bit which is a pressure reliefe valve apprently, and no-one can confirm if it's essential. There is a blank node to tap on the new casting and fit the old valve, but its an imperial thread I don't have a tool for.

Condensors looked fine, didn't disturb them when the bumper came off last year, so saying a prayer it will all work after so long apart.

I finally worked out why I missed this patently obvious damage - I was so concerned with moisture getting in the system, the second the pipes came free I bagged them with an elastic band. Never thought to check insode all the time they were off.

[Chillidoggy]

Sympathies. My heart sank as I undid the compressor connections. Alloy thread into a steel union - asking for trouble. Finally took me 7 packs of caustic soda and about three weeks of soaking to remove all the broken bits from my A/C and oil cooler pipework.