Aircon Capillary Tube

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Yes I know it's a long shot but... I've been rebuilding a NADA aircon heater box, and on intallation into the car I found that the capillary that runs from the heater matrix to the heater water control valve had been supplied snapped. This renders the unit practically useless, so I'm looking to either find a replacement, or find a company that can recreate / repair the capillary.

The tube runs from the heater matrix to a Ranco vacuum assisted water valve on the front of the heater box.

Any help greatly appreciated. :LOL:

Richard
 
This is a well known problem Richard. I've not yet met anyone who's solved it either! There are a couple of cars that have a similar valve - notably Jensen Interceptor, but they are all cable operated rather than vacuum capilliary. People I've spoken to with this problem have run their cars in A/C mode during the summer and not used them in the winter! The nearest I got to solving it was to think about fitting an entirely different type of valve and just using the vacuum signal to operate a servo motor.

It sounds like you are getting close to trying to recommission the beast! I had done a fair bit of preliminary thinking on this but didn't actually get to attempt the feat. There is only on source of information as to how its meant to work and that is the (very flashy) NADA hardback Owners Manual. If you don't have access to a copy I can scan for you. Some parts were available until fairly recently from Rimmers. The SD1 has a system which is clearly closely descended from the P6 one. In particular they had the vacuum servo's and the monster 7(?) way vacuum distributor valve, albeit with a different bracket. I don't know how the SD1 managed the water valve problem, but one solution might be to buy a scrap A/C SD1 and use whatever that had. Since it has the same control valve it must have had something along the same lines as the P6.

Give me a ring for a longer chat.

Chris
 
Thanks Chris, doesn't look good !

We have the aircon manual strangely enough, which details the operation etc, but unfortunately doesn't help much in this instance.

Ranco are still in business, so on the off chance I have fired an email over to them, see what comes back, if anything.

It's very annoying, as we don't really want to be fitting the engine etc, until we at least know we have a fighting chance of getting the A/C to work.It's pretty key feature of the car. We've had the cores pressure tested, and I've remade the rotten casing and replaced all the foam seals, so other than this we should be in a good position.
 
I saw there was already a topic about the “RANCO water valve and capillary,
close to my problem.

Maybe someone can help with an advice.
Car: Rover 3500S NADA – with air condition

Subject:
RANCO water valve, how can I disconnect the copper wire (red cable coating) from the water valve?

Story
The air/con is working, but the RANCO water valve is leaking, water drops are falling down on the automatic bell housing. I can not find a hole or something like that. The engine gets hot and the cooling water is steaming like in devils kitchen.

Question.
How can I change the RANCO water valve without removing the complete heater/Air con unit from the car? This would be a nightmare job.
How can I disconnect the copper wire from the water valve? Is this possible?
What is the function of this copper wire?
Really need some help.
Any help is very welcome.
kind regards
Richard
 
Hi Richard

Sorry, it's not a copper wire. That is the capilliary and it goes inside the heater box to take the temperature within. The valve then adjusts the water flow to give the defired temperature as set by the dial in the car. You can't take it off the valve without breaking it - and then you are into the same problem as everyone else with an A/C car.

It is therfore essential you fix your existing valve without separating valve and capilliary.

It is possible to buy a similar RANCO valve that doesn't have the capilliary. I suggest you buy one and see if you can transfer its innards to the one in your car.

Chris
 
hi all,
firstly sage green, the ranco unit screws on to the heater box with four self tappers. so no need to remove heater box. chris you are wrong ( see picture for clarification ) the capillary tube unscrews from the back of the valve, so if like the one in the photo, you can part it and braize the tube back on. as to repairing the leaking unit, it is something i have never done myself, so i must when i get some spare time, dismantle one and see if there is anything to be done. richard, the valve won't stop you from seeing if the air-con works. put engine in, bypass the valve until you either come up with a solution or ranco still do them, if they do i will have a new one as well ( keep us posted ) or use the jensen one, like i told chris when i was doing his car, it is the closest to the rover as you will get. basically rovers was over engineered ( like climate control in todays cars ) the capillary is there to keep the temperature spot on to what it is set at, e.g if you set the temp gauge to 24 degrees it will stay at that temp. without it the temperature will fluctuate a little. i.e. the jensen one.

ian
 

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Hi Chris and Ian.

Thank you, thank you,
Thank you for the quick response. This are really helpful advices and good news.
I was worried about to remove the complete heater unit (as per Workshop manual) and worried about the capillary. if I understood it right, the capillary is not really important.
I bought a Jensen RANCO valve on the internet a week ago. I will try to unscrew the capillary tube from the back of the valve, and…I will see what happens. I will keep you informed about the result.

best wishes
Richard
 
hi sage green,
yes you can live without the capillary tube. the jensen valve will be fine. i used one in my first car as i had the same problem a leaking diaphram.

ian
 
josephp6man said:
hi all,
firstly sage green, the ranco unit screws on to the heater box with four self tappers. so no need to remove heater box. chris you are wrong ( see picture for clarification ) the capillary tube unscrews from the back of the valve, so if like the one in the photo, you can part it and braize the tube back on. as to repairing the leaking unit, it is something i have never done myself, so i must when i get some spare time, dismantle one and see if there is anything to be done. richard, the valve won't stop you from seeing if the air-con works. put engine in, bypass the valve until you either come up with a solution or ranco still do them, if they do i will have a new one as well ( keep us posted ) or use the jensen one, like i told chris when i was doing his car, it is the closest to the rover as you will get. basically rovers was over engineered ( like climate control in todays cars ) the capillary is there to keep the temperature spot on to what it is set at, e.g if you set the temp gauge to 24 degrees it will stay at that temp. without it the temperature will fluctuate a little. i.e. the jensen one.

ian
Click to expand...

Hello to IAN and CHRISYORk.

on weekend I did the "water valve" job, and, it was much more simpler than I thougt. my used RANCO Jensen Interceptor water valve works , until now, :-.)
the capillary was easy to unscrew from the valve.....but it took about 5 minutes to unscrew, because it is a a long screw, it is narrwow in that aera, and I worked carefully - concerning the capilary - because you told me it is easy to break the capilary.....

thanks for your advices to both P6 guys
best wishes
Richard
 
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