My aircon in my GTi had very poor performance a couple of years ago. Lots of funny noises in the evaporator and cooling starting well then gradually failing during 30 mins of use.
This year it had lost all pressure and was not working at all. It was a R12 system. Greenfreeze is not available around here and R24 and 413a is difficult to find so I decided to go the conventional 134a route.
First though I had to cure the leak or leaks. The compressor clutch was very oily. The expansion valve had a small amount of oil on it and the supply connector on the condenser was loose.
So I fitted a new expansion valve. The old one had a lot of internal corrosion. Fitted a new drier, a good used Sanden compressor drained and refilled with 135cc of ester oil, an R134a service adaptor and renewed all the orings in the system.
Finally I took it to be vacuumed out and filled with 800 grams of R134a at a cost of £80.
The result is a fully functional system. Albeit with quite a lot of bubbles in the sight glass. More than I would expect coming from the output of the condenser.
Any thoughts on the reason for this - is 800g the correct amount ?
Aircon repairs.
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Jaba
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Aircon repairs.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
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tom
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2024. TxD 1.9D estate. 'Wheelybin' - x 12
Also, which compressor did you use?
There's a 7 piston and a 5 used in BXs.
The 5 is normally found on the 8 valve versions and the 7 on the 16V.
I don't know which one is used on the diesels, but would imagine the 5 piston one as the only difference I can find from info I can access is that the 5 runs at 4000 rpm with a 6000 downchange whilst the 7 works on 6000 rpm with an 8,000 rpm downchange and whilst it might not make a real lot of difference, I would imagine that based on displacement variances against operational rpm, there might be a tendency for it to battle a bit on full load at low revs if the wrong one was fitted.
Alan S
There's a 7 piston and a 5 used in BXs.
The 5 is normally found on the 8 valve versions and the 7 on the 16V.
I don't know which one is used on the diesels, but would imagine the 5 piston one as the only difference I can find from info I can access is that the 5 runs at 4000 rpm with a 6000 downchange whilst the 7 works on 6000 rpm with an 8,000 rpm downchange and whilst it might not make a real lot of difference, I would imagine that based on displacement variances against operational rpm, there might be a tendency for it to battle a bit on full load at low revs if the wrong one was fitted.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.
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Jaba
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Alan its the Sanden 709 7 cylinder job that is fitted. It came of a TZI. I have an SD709 fitted on my 8v GTi as well so have never seen a 5 cylinder compressor.
I have a Seiko Seiko SS-270SS1 fitted on my Turbo.
I am not at all sure what the downchange spec means in the Sanden manual that you mention. I didn't know a/c compressors had an auto gearbox.
I had a measure up of the pulley sizes and find that the compressor is slightly smaller than the crankshaft pulley so it actually revs higher than the engine.
Meanwhile my a/c is still working well but I will want to fit new seals to the leaking SD709. Is this a DIY job - assuming that parts are available and special tools are not required.
I have a Seiko Seiko SS-270SS1 fitted on my Turbo.
I am not at all sure what the downchange spec means in the Sanden manual that you mention. I didn't know a/c compressors had an auto gearbox.
I had a measure up of the pulley sizes and find that the compressor is slightly smaller than the crankshaft pulley so it actually revs higher than the engine.
Meanwhile my a/c is still working well but I will want to fit new seals to the leaking SD709. Is this a DIY job - assuming that parts are available and special tools are not required.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
Nothing scientific with the "downchange" terminology; it means exactly that. When cruising, speeds <6000 rpm but when you change down to overtake etc, the revs increase and it will handle it <8000 rpm.
I don't have access to the actual performance specs of the compressors but would expect that the load rating would be similar to that used on some marine applications whereby the load capability would be increased with revs, in other words, the higher the revs, the bigger the load it can cope with.
In this case however, I would guess that this is also tempered by the revs attained by the different engines and whilst a 700 series which is normally in the 16V would operate in a slower revving engine, that whilst it should operate in your milder conditions, it wouldn't work all that well where I am unless you were driving like Louis Hamilton all the time. By the same token, I could see problems on the horizon if a 500 were fitted to a 16V due to the revs those engines tend to run at as well as the fact that the upper end rev range would be well exceeded and could lead to the self destruction of the compressor.
It could be that over there they have used the 700 series on more models for reasons best known to the engineers, in which case they have probably altered other parts of the system such as the condensor to keep it all in balance.
This is a write up on the front bearings on the clutch but has some valuable info. I have never heard of this particular brand of compressor but could be some help.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=19794
This links to a Sanden service manual which shows all the info in detail.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=11617
Hope that's some help to you.
Alan S
I don't have access to the actual performance specs of the compressors but would expect that the load rating would be similar to that used on some marine applications whereby the load capability would be increased with revs, in other words, the higher the revs, the bigger the load it can cope with.
In this case however, I would guess that this is also tempered by the revs attained by the different engines and whilst a 700 series which is normally in the 16V would operate in a slower revving engine, that whilst it should operate in your milder conditions, it wouldn't work all that well where I am unless you were driving like Louis Hamilton all the time. By the same token, I could see problems on the horizon if a 500 were fitted to a 16V due to the revs those engines tend to run at as well as the fact that the upper end rev range would be well exceeded and could lead to the self destruction of the compressor.
It could be that over there they have used the 700 series on more models for reasons best known to the engineers, in which case they have probably altered other parts of the system such as the condensor to keep it all in balance.
This is a write up on the front bearings on the clutch but has some valuable info. I have never heard of this particular brand of compressor but could be some help.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=19794
This links to a Sanden service manual which shows all the info in detail.
http://www.frenchcarforum.co.uk/forum/v ... hp?t=11617
Hope that's some help to you.
Alan S
By the time you're old enough to know it all, you can't remember why you were learning.