For anyone with a non working air/con.

AlanS · Post by **AlanS** » Wed Apr 04, 2007 12:42 am

I've posted this on another forum, but seeing as you guys are heading into the hotter weather, thought it might be of interest to you also.

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Over the years, there have been a few BXs with non operational or marginal air/con.
The usual "I had it regassed a few weeks back but it only lasted a few days so the guy put some green dye in it and it was gone within 24 hours" has been heard many a time followed by us advising them to look at the T/X valve which always seemed to be a suspect and which in many ways, didn't really make sense when the exact same valve is commonly used in not only Cits but Pugs and even Mercs, yet they don't seem to have this "inherant problem"

Recently, I decided to look a bit closer at the air/con on my BX16V that has never worked as long as I have owned the car and whenever we have tried to do anything on it, either I didn't have the time to go through it properly or the equipment I needed wasn't available or my mate the fridgie was passing through and just called in and gave it a quick whack as he was passing. Again it would last only days, so this time I decided I'd do it right.
The T/X had already been replaced due to a nice oily stain in the vicinity of the TX, in fact it was dripping out of the bottom of the TX cover. Close inspection showed what was possibly the leak, but IMO, not conclusively. When pressure was applied to the compressor, it was noted that a leak was evident at the suction connection. New "O" rings made no difference but on closer inspection, it seems the hose may have ruptures/leaked internally and the pressure has built up between the inner and outer casings and caused the leak to appear at the crimped end near the elbow that connects to the compressor.
As a precaution, I removed the compressor and drained the many attempts' green dye from the sump of the compressor and stripped the head and valve plate off the compressor, washed, wiped and checked the valves and the plate for any signs of damage. It was all clear so I topped up the oil and refitted the compressor.
Removing the hose that ran from the firewall to the suction side was a right old job as it is fed through a small area between the battery carrier and the inner guard....fun, fun, fun.
Upon inspection it was discovered that this hose has an aluminium fitting that connects to a brass one that has a piece of 1/2" copper tube set in the middle of it and this tube was damaged at some stage; factory or one of the Sydney meat vendors we're not certain, however it was impossible for it to seal properly. Added to this, it also had a weird looking "O" ring in it which was black plastic and tapered. I've never seen anything like it and neither has anyone else. It is also made of plastic not rubber as they all used to do in those days, so I replaced it with a neoprene one. When I removed a hose from a car we had here, lo & behold it has one also, so we think it may be that due to the position this hose is in, directly above the exhaust pipe, that perhaps this was Citroens way of compensating for the heat factor. It could be that the taper is to allow for the strange angle or simply because being made of a hard material they didn't think the plastic would seal if normal "O" ring shape or that it might flatten out and leak; either way, it doesn't work as this one appeared to be leaking also.
We then get to another car with a chronic leak and lo & behold, it's got one and it appears to have had a slow leak too! We based this diagnosis on the fact that both had the dreaded green dye running down the threads and in one case a guy who is a mate of the owner along with the owner did a very meticulous UV examination of this entire system and couldn't find a trace of any leak which IMO is easy to explain. The fittings are recessed back into the firewall to an extent and surrounded by insulation which is black. Located directly above the exhaust I'd reckon the dye either never made it to the outside or was simply soaked up behind the insulation. The oil inside around the TX is also explaine when you see that the connection to this hose is on a piece of 1/2" copper tube that is about 8" long and runs from the T/X (Eaton block valve) to the firewall, hence any loose or leaking threads could quite easily spray the gas/oil combination all over the TX giving the impression that the TX "Dunnit" when in effect it was the fitting, as a result, in changing the tX you remove the fittings so any tradesamn worth his salt replaces the "O" rings and in the process fixes the leak. They don't have to touch the firewall fitting but most would just run a spanner over the sytem and possibly seal off any slack that may have developped in that tapered "O" ring and bingo, a fully sealed system.......................and the TX valve? Well I wonder how many perfectly good TX valves have been sent to the scrap yard?
Like the Butler we've always blamed the TX and like the Butler, perhaps he didn't do it.
Handy info for anyone running out of ideas trying to get their BXs air con to work though.

Alan S

Post by **docchevron** » Wed Apr 04, 2007 2:31 am

This is really useful stuff, thanks Alan. At some point this year I AM going to get the aircon kit in the TD, and I just know it's going to be a nightmare to make it work! So this and the other air-con posts I've bookmarked by you should be most useful!

Although, the onset of summer seems to have halted again, it's not far above freezing here!

AlanS · Post by **AlanS** » Wed Apr 04, 2007 5:33 am

The spanners you'll need for the refirgeration fittings on the firewall is another interesting one.
1/2" Whitworthe for the outer male fitting and for the inner female one I took a cheap 22mm spanner, ran it through an emery wheel and trimmed it out with an angle grinder. It ended up somewhere in the vicinity of a 26mm spanner.

I also used greenfreeze refrigerant which is magic stuff. Harmless and much more efficient than the 134a and as a bonus, the old R12 systems don't have to go through the full conversion caper, but I would still renew all "O" rings and the receiver dryer as a precaution.

Alan S

Post by **docchevron** » Wed Apr 04, 2007 12:07 pm

Whitworth!!

Good job I got plenty of those then!!

I have all new seals, it's really just finding the time and courage to rip the dash out and fit it all in, although I think actually installing it all will be easy enough. It's the wiring that scares me, I've got masses of loom, and no idea where it all goes!

Although Tom did offer to help out with that, so I may leave the car with him when that happens and go play with his CX!

Incidentally Alan, you wrote that the compressors are different on the TD and 16v. The kit I have came from a 16v, or at least I think I did, the condensor is definitley from a 16v, so will I need another compressor for the TD or will the 16v unit be ok??

Cheers
Chris G

AlanS · Post by **AlanS** » Wed Apr 04, 2007 7:52 pm

I'm not certain about the Diesels, but I know on the petrol 8 valve versions they are different.
I'd suggest you check out a guy who posts from over here as "ozziediver" or "rosscoe" as he has one of the few diesels out here and IIRC he fitted air/con last summer to it.
The thing I would be a bit sceptical of is that the 16V compressor is of the 7 piston variety and according to its specs its operating range is 6000 rpm with an 8000 downchange whereas the ones used in the 8 valve versions are 5 pistons and 4000rpm and 6000 downchange. The surface area of the condensor is also much smaller on the 16V due to its location in relation to the upper crossmember (the bit the bonnet catsh is fitted to) now whether that will affect its performance significantly I don't know, but I doubt Citroen would be fitting a component to a diesel expecting it to pull the revs a 16V does, but by the same token, there's always a chance that a slight varience in pulley sizes could accomodate for that.
Has Tom told you which system he fitted to his?
BTW, has your car got the penetrations already in the firewall for the air/con and have you also got the second (sucker) fan?

Alan S

Post by **docchevron** » Thu Apr 05, 2007 2:49 am

I know Rosscoe, well, in a PM kinda way, so I'll pester him for details!!

Not sure what system Tom has on his TBH. The kit I got came from Tom many years ago, and is still awaiting fitment!!

It's got the smaller condensor so it's defo from a 16v.
I have to use the 16v condensor in the TD anyway as I'm putting a mamoth intercooler behind the rad, so from that point of view it works out quite well really! I hope!!

But yeah, he gave me everything including the twin blower fans and recirculators.

Alas no, my TD doesn't have an air-con shell, but my valver does, so cutting the required holes in the TD will be easy enough, I'll just make templates from the valver and get the grinder out!!

i'm determined to get it all in and working this year, otherwise I'll just keep putting it off...

If the rest of the system is identical other than the compressor then I'll just get a diesel compressor, infact I have one from a diesel 306, which to all intents and purposes looks the same as the compressor I have already but assume it's the 5 piston type??

Cheers
Chris G

AlanS · Post by **AlanS** » Thu Apr 05, 2007 3:00 am

I've been thinking that Rosscoes just might be a 16V one as he had a 16V destroyed in a hail stoorm; I have the engine out of it sitting in my garage, but I can't remember if he started on the air con job before or after the hail did its thing.
If he's fitted up a 16V system entoto and it works OK, then you're safe as a bank.

Alan S

Post by **docchevron** » Thu Apr 05, 2007 3:04 am

Thats a good point. I think Brisn said that the air-con came from the 16v, so yeah, that sounds like a goer! I'll double check with him first though!

At least the compressor is easy to get at and change if needed!!

Thanks Alan!

Cheers
Chris G

DLM · Post by **DLM** » Thu Apr 05, 2007 1:02 pm

The aircon on Tom's TZD is the "standard" Citroen fitment, with all controls on the centre dash, as opposed to the setup which seems to crop on some later 16v's, which has an additional switch on the handbrake console (a whiff of aftermarket here?).

I think this second setup is the type you've got Doc - is that correct and does it help at all?

tom · Post by **tom** » Thu Apr 05, 2007 1:34 pm

Suppose I'd better clear this up. Grolliffe's system originated in a TZI 8 valve estate and the system that the Doc has came from a phase 1 sixteen valver.

Post by **docchevron** » Fri Apr 06, 2007 2:27 am

Yep, I've got the little buttons by the handbrake! Which I quite like! Bugger all idea how to wire them in, but they look pretty, and I like buttons!

I guess the time is rapidly approaching then that I should pull my finger out and fit all this stuff in the car! I want to change the dash anyway since it's still grey, and I've got a wiring fault in the loom affecting the N/S window reg that I could fix while it's all out!
So, I'll crack on!

Cheers
Chris G