E51 E51 Aircon Pipe Corrosion (Rear)

[Steve~Mk1]

I held off adding this 'fix' to the thread until I could see it worked / lasted more than 5 minutes.

Anyway when I got the bus in May 23 the ac worked but was quite weak, so had it re-gassed but never really used it as we never had any hot weather in 2023…Fast forward to May 24 and it was empty - gone in the usual spot where the pipe sits in the spongy foam in the rear cover 'arch'.

Reading earlier on that @brent hayes fixed his with araldite, I went a little bit further and got some 21mm ID alloy tube to sleeve the ac pipe - held on with araldite.

Keyed up the affected area with wet&dry paper - 400 I think. Cut out a length of the tube to go over that area, then cut that section in half across the length. Put araldite metal epoxy over the ac pipe and inside each sleeve, to stick the two sections of sleeve to the ac pipe, and the two cut joins together. Epoxy oozed out each end and each of the sleeve joins, so just smoothed that out with a bit of cardboard/makeshift spatula. Had a couple of cable ties on there too to hold it together till the epoxy cured.

The foam tube still rolled back over it so its unseen and after a full gas refill it's held pressure so I've got working ac at both ends This might not work if you have gaping holes in the ac pipe (or the pipe is torn open), but it was a quick/easy/painless fix and kept rear ac - think it took me about 30 mins to do start to finish.

 

[brent hayes]

Very good, long may it last

 

[WhatsThisFor]

I hope it holds...if not there is always plan B.

 

[Lpgc]

There's always plan C too... Swap out the leaking front to rear pipe for a good front to rear pipe. But unless you can get hold of a 2 or 3 part front to rear pipe you need to lower the rear axle to remove and refit a single piece front to rear pipe.... A job I've done a few times. The usual single piece front to rear pipe requires the rear axle to be lowered to fit it but the 2 / 3 piece pipes can be fitted without lowering the rear axle because they have a joint (that you can disconnect) allowing you to get the curved section over the axle.

I put the cause of the usual position leak down to electrolysis due to aluminium pipe with steel vehicle body. Usually by the time there are pinprick holes in the aluminium pipe the general area around the pinprick holes is very thin because it's also been eroded by electrolysis. Be careful doing any sorts of repairs because for example you don't want to try to key/sand it only to make it even thinner and make existing holes bigger or make more holes.

 

[Steve~Mk1]

There's always plan C too... Swap out the leaking front to rear pipe for a good front to rear pipe. But unless you can get hold of a 2 or 3 part front to rear pipe you need to lower the rear axle to remove and refit a single piece front to rear pipe.... A job I've done a few times. The usual single piece front to rear pipe requires the rear axle to be lowered to fit it but the 2 / 3 piece pipes can be fitted without lowering the rear axle because they have a joint (that you can disconnect) allowing you to get the curved section over the axle.

I put the cause of the usual position leak down to electrolysis due to aluminium pipe with steel vehicle body. Usually by the time there are pinprick holes in the aluminium pipe the general area around the pinprick holes is very thin because it's also been eroded by electrolysis. Be careful doing any sorts of repairs because for example you don't want to try to key/sand it only to make it even thinner and make existing holes bigger or make more holes.

Yes - I expect the pipe is quite thin to start with, then after nearly 20 years of corrosion (galvanic?) could be like rice paper, so you would have to tread carefully when sanding and a use relatively fine grade (400 is quite coarse on bodywork/paint jobs, but not so much on bare metals). Hopefully the use of the sleeve will reinforce the compromised section - found the ebay receipt - 25mm OD 2mm wall 21mm ID.

 

[toshistar]

Based on the common leak in the rear aircon pipe, has anyone actually had the pipe successfully replaced with an original part? If so where did you get it done and how much did it cost for parts and labour? Assume you can use good condition used/second hand breakers parts. Thanks in advance.

 

[Lpgc]

Based on the common leak in the rear aircon pipe, has anyone actually had the pipe successfully replaced with an original part? If so where did you get it done and how much did it cost for parts and labour? Assume you can use good condition used/second hand breakers parts. Thanks in advance.

I have changed the front to rear aircon pipe on two E51 Elgrands using 2nd hand front to rear pipes, I bought the 2nd hand pipes from an Elgrand breaker @stevemen

I forget how much the pipes were each but seem to remember the cheapest was around £150. Two different prices because although all original pipes were a single piece there were (for a time) some aftermarket pipes made that were 3 sections (had a couple of joints along the length), I bought one that was single piece, the other more expensive one was 3 section. The original single piece design requires the rear axle to be lowered to fit (otherwise you'll never thread it between the underside of the car and rear axle setup). With the multiple piece design you can thread the rear section between the axle and body then rejoin the sections. So the mutli-section pipes are more valuable (if you can get them) because you don't have to lower the rear axle to fit them. As said, I've fitted both (single piece and multi-section) pipes, so I've done it both ways. Just to be clear both pipes I fitted were 2nd hand, both removed from scrapped Egrands... and you would be lucky to be able to find a multi-section second hand pipe so it's more likely you would need to lower the rear axle to replace the pipe. It isn't too difficult to lower the rear axle but it's probably worth paying more for a multi-section pipe so you don't need to lower the axle if you can find one.

 

[Wurz]

Hi All. I've just deleloped a leak. Rear passenger side, green, feels slightly oily. Is this the Aircon and is that a bleed vv that needs nipping up? This was a bit of blind video. Not had time to take the wheel off and crawl under?

Any serious downsides if I leave it for a while?

Thanks all

 

[Lpgc]

Not easy to make out where we're looking...

If that is at the very rear where 2 short lengths of rubber pipe join 2 metal coolant pipes to 2 stubs from the rear heater core it could be the coolant bleed port for the rear heater core, just a rubber bung that's clipped around the metal bleed pipe that sticks down a bit through the floor. Be careful working with it because if there's any corrosion on it it could be very weak and you don't want to break it if it isn't already broken.

If it were a bit further forwards it could be AC refrigerant oil you're seeing but it seems more like we're looking near the very rear quarter.

 

[Wurz]

Not easy to make out where we're looking...

If that is at the very rear where 2 short lengths of rubber pipe join 2 metal coolant pipes to 2 stubs from the rear heater core it could be the coolant bleed port for the rear heater core, just a rubber bung that's clipped around the metal bleed pipe that sticks down a bit through the floor. Be careful working with it because if there's any corrosion on it it could be very weak and you don't want to break it if it isn't already broken.

If it were a bit further forwards it could be AC refrigerant oil you're seeing but it seems more like we're looking near the very rear quarter.

Thanks. Yes it's a bit further back than the nearside rear wheel. The second hose is almost in shot the leak is just behind them.

 

[Highway Dave]

As @Lpgc says , that looks like the coolant bleed as in this pic

 

[Wurz]

 

[LeStempy]

Yes. bleed spigot for the rear heat exchanger, probably just perished rubber, it's a push on cap.

 

[Bazildog]

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... View attachment 77237View attachment 77239View attachment 77240

are you here still? what did you use on the outside, looks like it will be doing a grand job

 

[Tino]

Jumping on the post, is this rubber pipe likely to be my air con issue?

 

[Bazildog]

Jumping on the post, is this rubber pipe likely to be my air con issue?View attachment 115238View attachment 115239

I will go with a yes. Is your rad full?

 

[Tino]

I will go with a yes. Is your rad full?

Not checked, collected from Vine Place last weekend and has gone through their PDI list (Air Con is to be blanked off on Wed) ideally I'd like to keep the rear working if possible

 

[LeStempy]

Jumping on the post, is this rubber pipe likely to be my air con issue?View attachment 115238View attachment 115239

No, they are coolant pipes from the engine to the rear heater. The refrigerant pipes are aluminium.

 

[Tino]

No, they are coolant pipes from the engine to the rear heater. The refrigerant pipes are aluminium.

That was what I thought but saw some similar pictures whilst skimming through this post

 

[Tino]

My main pipe is covered in a foam insulation layer is that standard practice? inside the viewing flap all looks dry and ok? Just had a quick poke with my phone light so will get underneath tomorrow.