Water return hose

[SENC]

Looks like mine is shot.

Are these temporarily fixable with a new piece and a spline joint, or must I replace the entire pipe? Other temp fix alternatives? If full replacement is the only real option, is that an entire dash out, or is it doable through the radio opening? Any tips?

[billwill]

You can probably chop out a chunk of perished heater hose and insert a piece of new rubber, I think you might be able to use a piece of 15mm copper pipe and two jubilee clips to join the old to the new rubber pipes.

It's only a bit of ordinary water plumbing.

[SENC]

Thanks Bill. Can you confirm whether the piping is 5/8" or 1/2" ID?

[billwill]

Thanks Bill. Can you confirm whether the piping is 5/8" or 1/2" ID?

Sorry I don't remember, it's many years since I last changed a bit of heater hose.

[SENC]

Thanks, and i've now confirmed it is 1/2" id.

[richardcox_lotus]

From memory, if you remove the glove box & radio & you can get access. Need to drain the level a little.

Regards
Richard

[69S4]

That's the easier side to replace (although 'easy' is a relative term) as you can get to the heater spigot by just removing the glove box. I used a plastic hose joiner on the other heater hose when I had the same problem and it lasted about 10 yrs before the whole hose started to rot. From memory it came from the local garden centre. Hose is 1/2" id.

[SENC]

That's the easier side to replace (although 'easy' is a relative term) as you can get to the heater spigot by just removing the glove box. I used a plastic hose joiner on the other heater hose when I had the same problem and it lasted about 10 yrs before the whole hose started to rot. From memory it came from the local garden centre. Hose is 1/2" id.

Thanks Stuart - mine is LHD, so glove box isnon the wrong side in my case. Going to go the splice route first, but have ordered a proper hose as a backup.

[MarkDa]

Whilst in theory it's easy enough to release the clamp on the heater matrix if the pipes been there a long time then it'll be fairly stuck to the spigot.
I'd be inclined to splice in a new length when you cut the old pipe you'll get a good idea of whether it's rotten or not.

[SENC]

Cut the hose to find the inlet to the water valve totally occluded.

Tried digging a bit out, but was occluded as far as I can reach with a pic.

The hose was only occluded 1/2 " or so going the other direction, and clear by 3". Other than getting the valve off and either clearing the stoppage entirely or replacing it, is there anything else you'd recommend? Should I back flush the heater to see what i wash out going the other direction before hooking it back up?

[MarkDa]

I think that you'll probably need to replace the valve.
In UK they're cheap and easy to obtain..
Removal is a bit of a pig as the engine has to be tilted to allow valve to clear body work.
It's always worth flushing back and forth with a garden hose while you're disconnected.
With gunge like that present you'll want to ensure that the main system is clear as well.

[joe7]

Watch that water pressure from the hose as it is about 30 - 35 lbs where as the cooling system runs about 10 lbs give that's the pressure on the cap. Don't want to blow out the heater matrix!

[SENC]

Replaced the valve today. Did not have to tilt the engine (perhaps LHDs are different?), but did have to remove the temperature bulb. The new valve installed and sealed quite well with a bit of plumbing sealant, but the bulb fitting has very few threads and I didn't want to over torque - I seem to have a VERY SLIGHT leak around the bulb - not noticeably dripping, but if I rub a paper towel under it after running I can collect a drop of yellow antifreeze.. Have others experienced this?

Perhaps reinstall with some loctite, or JB Weld as suggested in this thread for the valve?
lotus-twincam-f39/water-valve-loose-fit-t41655.html

Pictures follow. Thanks for your thoughts.

[MarkDa]

That's good progress.
You could try plumbers PTFE tape to help seal the connection - it's a taper thread so one extra turn makes a big difference.

[Bud English]

Looks like most of the adapter threads are still in the head. I don't off hand remember what what the adapter threads are (3/8 BSP to 5/8 UNF ??), but I think they are available. Unless, of course, you don't think the bulb will survive removing it from the adapter. That would be expensive if it didn't.