E51 E51 Aircon Pipe Corrosion (Rear)

[Rayc]

Refurb done...

got rid of all the foam stuff & made some proper gaskets to keep the crud out, (the astute of you may notice what from)

Coated pipes & inside with marine grease then fastened cover on with stainless bolts...

 

[Nevillerover]

I’m having my E51 re-rustproofed in a few weeks and I want to show the man exactly where he needs to proof these pipes but I have found all the photos confusing.
There is a big “box” with a rubber duck drain thing in the bottom with two pipes going into the front of it but I’m guessing it is not inside this box. Are these two exposed pipes normally covered with a box with lid and it is inside that which needs doing? If so, as mine is exposed, I’d just get him to slather it with stuff.

 

[cjholding]

The air con pipe box is directly behind the nearside rear wheel. A single foam insulated pipe enters through a mousehole through a front corner of the box.

There is also the rear heater matrix which has two water hoses connected to it.

 

[Nevillerover]

so I think you mean inside this odd opening and the thick pipe going into it?

 

[cjholding]

Yes, your inspection hatch is missing.

 

[Nevillerover]

thanks once again Charles. Actually might be better without the cover, will Let it breath and dry out.
I will make sure it is well coated.

 

[cjholding]

Simon reckons removing the cover is the way to go.

 

[FilX]

Looks like I have joined the club after enjoying the back and front aircon in the last few days! Would you say it’s the aircon? Or the box needs opened to check where it comes from. Looks green on the ground but when you touch the box where it has leaked from it’s yellow. The coolant in the car is green but the radiator is full - doesn’t look like it has lost any (although the leak in the back is small so far).

 

[skystalker1]

Looks like I have joined the club after enjoying the back and front aircon in the last few days! Would you say it’s the aircon? Or the box needs opened to check where it comes from. Looks green on the ground but when you touch the box where it has leaked from it’s yellow. The coolant in the car is green but the radiator is full - doesn’t look like it has lost any (although the leak in the back is small so far).

its leaking ,remove the box, metal filler works for a while, will last the rest of the summer anyway blanking plates can be bought but last time I looked they were out of stock from BMR .

 

[cjholding]

It's only Aircon in the box, the coolant lines for the rear heater are in front of the rear wheel not behind it.

 

[FilX]

its leaking ,remove the box, metal filler works for a while, will last the rest of the summer anyway blanking plates can be bought but last time I looked they were out of stock from BMR .

Thanks mate - yeah - i messaged Brian to check bout the plates. Funny timing - been saying for a while how impressive is that a 19 year old car has aircon in the back while a lot of modern cars don't. I do have a 2 year old in the back seat so aircon in hot weather is good but living in Scotland can do with just the front most of the time. Was aware of the issue and asked for the pipes in the box to be coated as well when the car was imported and undersealed - just opened the flap and not sure they were but as it has been said - the design is not great and like everything of this age - it is expected that might fail at some stage.
I'll try and remove the whole box - from reading this thread sounds like it doesn't do much anyway.

 

[Lpgc]

The rear heater unit does contain both aircon evaporator and heater matrix... But by 'box' you're probably referring to the external box that houses the rear heater unit. Still, strictly speaking there is both an AC evaporator and heater matrix in there.

The green drips certainly look like they're coming from inside the box but that can be the case if the aircon pipes external of the box leak and green AC oil runs inside those pipe's outer insulation to the inside of the box.

I wouldn't at this stage be removing the rear heater box but would remove the external box cover and peeling back AC pipe insulation to see if it was the external (of the box) AC pipes that were leaking.

The rear AC and heater don't seem much less powerful than the front... So I wouldn't say "They don't do much" but it's true that once a comfortable inside temperature is reached (including in the rear) the rear heater/AC switched to 'Auto' normally only runs with a fan speed of 1 (mark as indicated by heater control screen). The biggest benefit of rear heater and AC may be in how quickly the rear gets to the comfortable temperature but if I were a backseat passenger in this recent hot weather (or in cold winter weather) I think I'd prefer the rear heater/AC to be working. And on particularly hot days when recirc might normally be preferred, if rear AC didn't work it'd probably be better to use the new air setting rather than recirc (or the front end could be a lot cooler than the back seat).

 

[skystalker1]

Thanks mate - yeah - i messaged Brian to check bout the plates. Funny timing - been saying for a while how impressive is that a 19 year old car has aircon in the back while a lot of modern cars don't. I do have a 2 year old in the back seat so aircon in hot weather is good but living in Scotland can do with just the front most of the time. Was aware of the issue and asked for the pipes in the box to be coated as well when the car was imported and undersealed - just opened the flap and not sure they were but as it has been said - the design is not great and like everything of this age - it is expected that might fail at some stage.
I'll try and remove the whole box - from reading this thread sounds like it doesn't do much anyway.

can you let me know if Brian has them in stock yet ,I don't have a mobile at the moment I have a slow leak but the metal filler has slowed it right down should last me the summer .

 

[FilX]

can you let me know if Brian has them in stock yet ,I don't have a mobile at the moment I have a slow leak but the metal filler has slowed it right down should last me the summer .

yes - he does. And I ordered some (might be hastily but we will see).

 

[FilX]

The rear heater unit does contain both aircon evaporator and heater matrix... But by 'box' you're probably referring to the external box that houses the rear heater unit. Still, strictly speaking there is both an AC evaporator and heater matrix in there.

The green drips certainly look like they're coming from inside the box but that can be the case if the aircon pipes external of the box leak and green AC oil runs inside those pipe's outer insulation to the inside of the box.

I wouldn't at this stage be removing the rear heater box but would remove the external box cover and peeling back AC pipe insulation to see if it was the external (of the box) AC pipes that were leaking.

The rear AC and heater don't seem much less powerful than the front... So I wouldn't say "They don't do much" but it's true that once a comfortable inside temperature is reached (including in the rear) the rear heater/AC switched to 'Auto' normally only runs with a fan speed of 1 (mark as indicated by heater control screen). The biggest benefit of rear heater and AC may be in how quickly the rear gets to the comfortable temperature but if I were a backseat passenger in this recent hot weather (or in cold winter weather) I think I'd prefer the rear heater/AC to be working. And on particularly hot days when recirc might normally be preferred, if rear AC didn't work it'd probably be better to use the new air setting rather than recirc (or the front end could be a lot cooler than the back seat).

Cheers Simon - very insightful as usual. I did go through all the post (quickly but did) and picked up the point about the rear heater unit being in this area as well - that's why was thinking that might not be a straightforward - yes it's the AC pipe.
And yes by the box - I meant the external box with the flap (that I have on the picture - probably not easy to identify from this pic). Ok - will need to get somebody to look at it and confirm where the leak comes from.

And completely agree with you - I would rather have the back heater and Ac working (I assume the heater works if the back AC gets blanked - as you mentioned the AC pipes and heart pipes are different as i assume is on all cars?! - otherwise the car goes before the winter) - if there was somebody close by willing to do the work - I will happily pay for it - will even travel (although this becomes a challenge if it is too far but willing to do it to get it sorted properly). With young family (and baby on the way) and this currently being the only car this is not ideal by a long stretch but a reality with an old car and being a grey import. I take it if the rear AC gets blanked - it still can be sorted properly afterwards (with pipes replaced)? Although most likely the car ill be replaced before this happens.

If you are willing to sort few things out - happy to come and visit you and make it worthwhile for both of us (need a calibration of the LPG system as well - so can wrap it all up) .

 

[Rayc]

The rear external box cover can easily be removed for inspection (held on by two 10 mms bolts)...
It's a good preventive easy job to coat (I used marine grease) the air con pipes & box interior to prevent corrosion...
Its a bad design where it's located for our roads as it gets all the crud thrown up from rear wheel...

 

[chrisbrown175]

I also noticed the dreaded green liquid from the same spot however currently the air con seems to be working fine. My inspection hatch / box is badly corroded and half of it is missing. Is it possible to buy a replacement?

Am I correct in thinking that the pipe will only leak when the rear air con is in use? I tend to only use the front air con so would not using the rears effectively stop the problem getting worse and avoid the need for blanking plates and re-gassing?

 

[FilX]

I also noticed the dreaded green liquid from the same spot however currently the air con seems to be working fine. My inspection hatch / box is badly corroded and half of it is missing. Is it possible to buy a replacement?

Am I correct in thinking that the pipe will only leak when the rear air con is in use? I tend to only use the front air con so would not using the rears effectively stop the problem getting worse and avoid the need for blanking plates and re-gassing?

I am not sure - the other guys will be able to answer that. But I'll see tomorrow if using the front reduces/stops the leak - might be hard to tell as I haven't removed the box yet so there might be liquid still left there.

I did have both front and back aircon on full blast for short period of time last few days - just to cool the car quickly - I wonder if this has caused/made worst the leak.

 

[skystalker1]

Think it leaks even if you don't use it ,mine worked in the summer but by next summer it was empty even though I did not use it in winter .

 

[brent hayes]

The hole system empties , front and rear is one system, with two units that can be selected independent of each other