Can this coolant hose joint be changed easily?

[GreenGoddess]

I took my car to a local garage yesterday so I could have a good look around underneath it with a mechanic. It was in generally great condition but we noticed that a coolant hose had been leaking (looks to be a very small leak but definitely noticeable). It is leaking where a rubber hose joins onto a metal pipe. The problem is that it looks like it's in a place that would be very difficult to access. Please see the attached photos. Have any of you any idea what work would be involved in fixing this?

[andydclements]

The challenge is that the metal bit in question isn't a nice simple union, it's a long aluminium pipe that runs the length of the subframe backbone.  You can access it but it's awkward, might be worth just lifting the engine off the mounts and raising it a couple of inches to help.

[GreenGoddess]

Thanks. That is well beyond my capability. Can the pipe and hose be removed as one complete unit and slid out somehow without having to raise the engine?

[Sparky]

You might be lucky and the union will clean up and reseal with a new clip, but pipe corrosion is a common failure point.  The pipe will only come out intact with engine removed or lifted a fair bit.  A couple of non-original (and, franky, more durable) fixes exist if that's not desirable.  One involves fabrication and installation of a semi-flexible pipe assembly through the master gearchange aperture.  The other requires a visit to your local DIY store for flexible plastic plumbing pipe.  It's a lot of fun either way, as is getting the old one out (pull-bend-pull-bend und so weiter).

[GreenGoddess]

Thank you Sparky. It's a shame because my car had a full engine rebuild just 600 miles ago so that could have been taken care of at the same time. But I wasn't the owner then, I've only recently bought the car.

[CarBuff]

Accessing that union seems a LOT harder than on our X180.🥵

Yes, corrosion of the aluminuim pipes can be an issue, especially on cars that have not run for long periods.

 

It is always advisable to apply a non-hardening sealer like Hylomar Blue to these unions.

 

[GreenGoddess]

18 minutes ago, CarBuff said:

It is always advisable to apply a non-hardening sealer like Hylomar Blue to these unions.

 

Do you mean apply the sealer when replacing the pipe? Or could I apply the sealer to the leaking pipe to help stop it leaking?

[CarBuff]

Apply the sealer whenever breaking apart a rubber-hose-to-aluminum joint. Coat the 'pitted' aluminum. (Make sure that the pipe isn't ready to break---had that on an S4s heater hose once, needed to shorten it & double-clamp)

 

Applying it from 'outside' won't help. (You are an optimist, I can tell...)☺️

[GreenGoddess]

Thanks CarBuff. I suppose it's not ideal being an optimist when owning an old Lotus 😂

[drdoom]

Absolutely no doubt it's best to be a pessimist as owner of a Lotus when it comes to maintenance. That way one may be appropriately (?) optimistic when shredding pavement at the limits of adhesion! 😁

[910Esprit]

If it's the smaller alloy heater pipes, I changed these on my G Turbo, in situ, without touching the engine, but the fuel balance needed to be removed.    There is a thread about it somewhere.   (NB I suspect later cars have a different sump, so it's only possible on earlier cars) 

There should also be a few spare inches of pipe at the front of the car that should allow the pipe to be pushed back to gain a little more access, or possibly get rid of the decomposed section.

 

[GreenGoddess]

14 hours ago, 910Esprit said:

If it's the smaller alloy heater pipes, I changed these on my G Turbo, in situ, without touching the engine, but the fuel balance needed to be removed.    There is a thread about it somewhere.   (NB I suspect later cars have a different sump, so it's only possible on earlier cars) 

There should also be a few spare inches of pipe at the front of the car that should allow the pipe to be pushed back to gain a little more access, or possibly get rid of the decomposed section.

 

Thank you. If you have any idea where that thread is located please let me know. I'd be interested in reading it.

[910Esprit]

 

@GreenGoddess

I was looking for it myself (unsuccessfully)

It was called something like 'ugghhh water leak'  I recall.   Happy hunting!  

 

[ekwan]

I replaced mine with a stainless steel pipe that came out through the front after the radiator was removed. Bought a length of stainless, got a beading rolled in at both ends by a machine shop. Hopefully, stainless steel would last a lifetime.

[GreenGoddess]

3 hours ago, 910Esprit said:

 

@GreenGoddess

I was looking for it myself (unsuccessfully)

It was called something like 'ugghhh water leak'  I recall.   Happy hunting!  

 

Here you go: 

 

[Andyww]

As already mentioned the aluminium pipes all develop pinholes where the hoses join. It might just be a loose clip but unfortunately more likely to be pinholes.

I have changed the heater through-chassis pipes with engine in. The centre rad fan has to be removed for clearance.

Then you can push the pipe forward as far as it will go, almost touching the rad. They have to clear a cross-shaft in the chassis backbone where the seat belts mount to. The 2 heater pipes run under it and they have a piece of rubber hose glued on to prevent rattling.

Feed a fibreglass cable-pushing rod through the pipe so it comes out the front end.push pipe back and sideways to direct it through the gear linkage hole. With a bit of bending it should come out, following the path the gear linkage takes. Leave the fibreglass rod in. Then push the new pipe in, the same way, the rod should guide it through the grommet at the front end. Angle the pipe so its as far down as possible at the rear and push it back so it goes under the seat belt mouinting shaft. Push the rod back from the front and route it through the rear grommet then push the pipe back through the grommet. 

Good access is needed under the car for this, ideally on a lift, and 2 people would make it easier also. A phone borescope camera might be useful.

 

[GreenGoddess]

Thanks Andy, they are really good tips.

I am tempted to just leave it for a while. I am trying to find a "Rent-a-Ramp" type establishment in my area (difficult in Cumbria) where I could take it to work on things like this.