Well. the system had lost 95% of its gas by last Friday and the TX valve was stripped and cleaned and re ringed on Saturday. This morning I took the car to Citronics and Craig vacuumed the system down for long enough then refilled it. I have no slimy leaks from the valve and no bubbles in the drier. I'll keep my fingers crossed although paranoia has now set in as I suspect that it isn't as cold as it was this morning but it might just be me!
I wonder how the Bolt is getting on with his? Good luck Bernie!
The BX aircon saga: part XXV11
Moderator: RichardW
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tomsheppard
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Well, I've fitted the new condensor and fixed the top with rubber grommets. Seems quite secure.[:)]
Today I had the new pipe made up with the R134a connector built in to the end fitting. ( A bit neater than an adapter). Nitrogen test shows NO leaks.[:)]
They cannot gas up till Friday the 13th, like you Tom paranoia has set in[xx(]
Today I had the new pipe made up with the R134a connector built in to the end fitting. ( A bit neater than an adapter). Nitrogen test shows NO leaks.[:)]
They cannot gas up till Friday the 13th, like you Tom paranoia has set in[xx(]
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tomsheppard</i>
I wonder how the Bolt is getting on with his?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Showing your age Tom[:D][:D]
I wonder how the Bolt is getting on with his?
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Showing your age Tom[:D][:D]
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tomsheppard
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In the lands of the North, where the Black Rocks stand guard against the cold sea, in the dark night that is very long the Men of the Northlands sit by their great log fires and they tell a tale...
This is the saga of Tomshep the Tom, once bidden by the people of Hotwater Valley to fight the Ice Dragon and met its cold breath...... how the dragon fled, and who it was that carried the cold treasure back to its rightful place.
Perhaps I'm showing my age too .........
This is the saga of Tomshep the Tom, once bidden by the people of Hotwater Valley to fight the Ice Dragon and met its cold breath...... how the dragon fled, and who it was that carried the cold treasure back to its rightful place.
Perhaps I'm showing my age too .........
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tomsheppard</i>
Well. the system had lost 95% of its gas by last Friday and the TX valve was stripped and cleaned and re ringed on Saturday. This morning I took the car to Citronics and Craig vacuumed the system down for long enough then refilled it. I have no slimy leaks from the valve and no bubbles in the drier. I'll keep my fingers crossed although paranoia has now set in as I suspect that it isn't as cold as it was this morning but it might just be me!
I wonder how the Bolt is getting on with his? Good luck Bernie!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Tom,
If the air/con has been run for a long period of time or if the fresh air vent has been left open whilst it was operating, the habit that BX air/cons have of continuous running will cause frost to grow over the actual fins of the coil. These must be kept as clear as possible which is why the norm is that the thermostat cycles the system, a thing that sometimes doesn't always happen with a BX hence the extra cold temps, as well as the operating pressures being such that they don't get cold like a freezing chamber gets cold, but get to below freezing point just the same.
To oversimplify the matter, effectively air being forced over the cooling coil when it's clear will be passing over a coil which is about say -3 which then gets to about +3 as it enters the car. If however the coil is iced, the coil is about 0 the air passing over the ice (ice incidentally then becomes an insulator - mad but true) is then coming out of the vents at possibly +15/20 and ice will build up on itself until it blocks the flow of air over it, at which point it becomes totally useless until the coil has the ice melted off it.
The other point also is, if any contamination gets into the system such as moisture or dirt, this will effect the efficiency. Moisture is intermittent; almost like a strange thermostat as it will freeze then stop freezing, restart again, maybe stay off altogether until next time you drive the car whereupon it can operate or not depending on the amount of moisture & where it keeps getting trapped in the system; usually the T/X valve oriface. It can occasionally happen that the moisture will circulate in the system and suddenly decide to trap itself in the filter/dryer. (You may also win the Lotto on Saturday.)
Dirt contamination can start off OK but then will progressively block a filter somewhere until the system just shuts down. Once turned off, the pressures balance and the dirt goes back into the system only to repeat the dose at the next use.
The adjustment on the T/X can also cause this symptom. If it's too open it will allow too much gas through into the evaporator and will hold the back pressure too high; this can be detected by feeling the suction (return line) and seeing if it tends to freeze as the coil temp falls inside the car, followed by either continued freezing or a sudden flash off of the ice on the suction which often indicates the back pressure has risen too high to allow the coil to come down to temp. If it is set too short or the adjustment screw too far in, this will be shown on a set of gauges where it will show too low a back pressure. A test of sorts for this could be if the compressor cuts out with the inside temp obviously too high for it to be done by the thermostat; in other words, your LP safety switch has detected it going into vacuum and shut it off.
In a case such as this, the actual coil will overfreeze in one section, block itself off for air circulation and the system then proceeds to pump itself down.
Long winded I know, but no simple answers in this game.
Alan S
Well. the system had lost 95% of its gas by last Friday and the TX valve was stripped and cleaned and re ringed on Saturday. This morning I took the car to Citronics and Craig vacuumed the system down for long enough then refilled it. I have no slimy leaks from the valve and no bubbles in the drier. I'll keep my fingers crossed although paranoia has now set in as I suspect that it isn't as cold as it was this morning but it might just be me!
I wonder how the Bolt is getting on with his? Good luck Bernie!
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Tom,
If the air/con has been run for a long period of time or if the fresh air vent has been left open whilst it was operating, the habit that BX air/cons have of continuous running will cause frost to grow over the actual fins of the coil. These must be kept as clear as possible which is why the norm is that the thermostat cycles the system, a thing that sometimes doesn't always happen with a BX hence the extra cold temps, as well as the operating pressures being such that they don't get cold like a freezing chamber gets cold, but get to below freezing point just the same.
To oversimplify the matter, effectively air being forced over the cooling coil when it's clear will be passing over a coil which is about say -3 which then gets to about +3 as it enters the car. If however the coil is iced, the coil is about 0 the air passing over the ice (ice incidentally then becomes an insulator - mad but true) is then coming out of the vents at possibly +15/20 and ice will build up on itself until it blocks the flow of air over it, at which point it becomes totally useless until the coil has the ice melted off it.
The other point also is, if any contamination gets into the system such as moisture or dirt, this will effect the efficiency. Moisture is intermittent; almost like a strange thermostat as it will freeze then stop freezing, restart again, maybe stay off altogether until next time you drive the car whereupon it can operate or not depending on the amount of moisture & where it keeps getting trapped in the system; usually the T/X valve oriface. It can occasionally happen that the moisture will circulate in the system and suddenly decide to trap itself in the filter/dryer. (You may also win the Lotto on Saturday.)
Dirt contamination can start off OK but then will progressively block a filter somewhere until the system just shuts down. Once turned off, the pressures balance and the dirt goes back into the system only to repeat the dose at the next use.
The adjustment on the T/X can also cause this symptom. If it's too open it will allow too much gas through into the evaporator and will hold the back pressure too high; this can be detected by feeling the suction (return line) and seeing if it tends to freeze as the coil temp falls inside the car, followed by either continued freezing or a sudden flash off of the ice on the suction which often indicates the back pressure has risen too high to allow the coil to come down to temp. If it is set too short or the adjustment screw too far in, this will be shown on a set of gauges where it will show too low a back pressure. A test of sorts for this could be if the compressor cuts out with the inside temp obviously too high for it to be done by the thermostat; in other words, your LP safety switch has detected it going into vacuum and shut it off.
In a case such as this, the actual coil will overfreeze in one section, block itself off for air circulation and the system then proceeds to pump itself down.
Long winded I know, but no simple answers in this game.
Alan S
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tomsheppard
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Thanks Alan. I have been doing some tests and I'm not at all sure that the system is entirely tight. The drier window sometimes shows empty and then clouds over slowly and it cycles like that. The thermostat (Thermistor) is controlling the system and it is cutting in and out even at maximum cooling set. There is definitely no ice on the coil. (Ive got the side cover off to check.) I am beginning to wonder if my specialist has vacuumed down the system correctly as the efficiency seems intermittent, suggesting moisture. Dunno! I think I'll have the system drained if it gets worse (Which I think it will) and get a better monkey to put a trace dye in to check for leaks; after all it is not the system's fault if I haven't got it tight. As with all mechanisms, one fault can mask another giving peculiar results so you need to hang on to your logic and your sense of humour. Character building this job! I've been in contact with DLM to see if GSF are still listing Ice Dragons. It is always as well to have a backup.
Tom,
Disregard the window in the receiver/dryer because on R134a this can show cloudy even when it is fully charged; it has no relevance any more.
If there is a strong element of doubt about the system being moisture contaminated, replace the dryer sooner rather than later as internal moisture if left can create corrosion and whilst a small amount can be withdrawn with the vacuum pump, a solid contamination will keep coming back to haunt you and cause more cost in the long term than replacing th dryer.
I'm not 100% au fait with the latest in charging stations but I know some time ago, these systems had digital readouts that gave a reading on the vacuum in the system and to leave one on for 24 hours particularly if there were any suspicions of moisture was quite common. Even up to 5 days wasn't uncommon. It was then left and the readings taken over a period of another couple of days and from this it could be deduced if the system had moisture, the extent of the contamination or whether it had a leak.
I think to get some peace of mind, you may have to try to find someone with about that standard of equipment and expertise.
Alan S
Disregard the window in the receiver/dryer because on R134a this can show cloudy even when it is fully charged; it has no relevance any more.
If there is a strong element of doubt about the system being moisture contaminated, replace the dryer sooner rather than later as internal moisture if left can create corrosion and whilst a small amount can be withdrawn with the vacuum pump, a solid contamination will keep coming back to haunt you and cause more cost in the long term than replacing th dryer.
I'm not 100% au fait with the latest in charging stations but I know some time ago, these systems had digital readouts that gave a reading on the vacuum in the system and to leave one on for 24 hours particularly if there were any suspicions of moisture was quite common. Even up to 5 days wasn't uncommon. It was then left and the readings taken over a period of another couple of days and from this it could be deduced if the system had moisture, the extent of the contamination or whether it had a leak.
I think to get some peace of mind, you may have to try to find someone with about that standard of equipment and expertise.
Alan S
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tomsheppard
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FYI,
The last time I priced a charging station was about 10 or 12 years back and they were from A$8000 - $12,000 for the bare bones variety.[:0][:0][:0][:0]
I know the Aussie Dollar a.k.a. Pacific Pesos ain't worth all that much, but I think you might be looking a bit "overkill" buying this for one job.[:D][;)][;)][;)]
Alan S [8D]
The last time I priced a charging station was about 10 or 12 years back and they were from A$8000 - $12,000 for the bare bones variety.[:0][:0][:0][:0]
I know the Aussie Dollar a.k.a. Pacific Pesos ain't worth all that much, but I think you might be looking a bit "overkill" buying this for one job.[:D][;)][;)][;)]
Alan S [8D]
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tomsheppard
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tomsheppard
- Posts: 1801
- Joined: 19 Dec 2002, 14:46
- Location: United Kingdom
- My Cars:
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tomsheppard</i>
Lots of our garages have them so they won't be that expensive. What they (and I) lack is expertise in their use. A decent vacuum pump and gauge won't be very expensive. I'll start there.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Sounds like they're using the kind of stuff we declared obsolete 20 years ago; this might explain why the problems are arising.
If all you need is something to suck air out, grab an old fridge sealed unit, wire direct through the relay and silver solder a 1/4" male flare fitting to the suction side. It will give you 28" of vacuum and cost nothing. You will need a gauge though; problem is, I don't know what your laws are regarding disposal of gas and these days it may be very illegal. I know you wouldn't get away with it over here now.
Alan S
Lots of our garages have them so they won't be that expensive. What they (and I) lack is expertise in their use. A decent vacuum pump and gauge won't be very expensive. I'll start there.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Sounds like they're using the kind of stuff we declared obsolete 20 years ago; this might explain why the problems are arising.
If all you need is something to suck air out, grab an old fridge sealed unit, wire direct through the relay and silver solder a 1/4" male flare fitting to the suction side. It will give you 28" of vacuum and cost nothing. You will need a gauge though; problem is, I don't know what your laws are regarding disposal of gas and these days it may be very illegal. I know you wouldn't get away with it over here now.
Alan S