Coolent leaks and levels

[stevebow]

Apologies in advance for the rambling post, hopefully it makes sense and someone will be able to help with this problem, if indeed it is a problem.

I've had constant issues with coolent leaks, first radiator so now have a new radiator, also replaced hoses with samco set, got it back from the garage and found coolent leaking again not pleased with the garage so thought id try to find out where the leak is and sort it, after tightening up some hose clamps it seems to have stopped the leaks all bar a very small drip from bottom hose.

But being extra cautious I'm checking the levels when cold after a run out. The other day I checked it and the header tank was almost empty so topped up with coolent went for a drive all seemed fine, then checking for leaks nope all good great, the next day when I opened the header tank the coolent level went from half to almost overflowing.

Is this normal behaviour, can the system be sucking in air or was the level when I topped up artificially low or could there be an air lock somewhere.

The garage said they did a sniff test on the coolent and all was ok. It drives fine with no overheating temp is steady just under a quarter and raises a bit when driving hard, sitting in traffic for a while temp goes up to half or three quarters can't remember then fans kick in and goes back to just under a quarter.

[GeoffSmith]

Did you bleed the system (under nearside headlight pod)?

[stevebow]

I haven't, I assumed the garage would have done that but as they didn't tighten the jubilee clips enough, it's something to look at, thanks

[alan e]

And have you put the heater onto the hot setting.

[stevebow]

Yeah heater was set to hot

[Rambo]

Sounds like you definitely have an air lock. Suggest you bleed thoroughly and then re-check

[RonR]

Don't be too harsh on the garage who fitted your hoses.
I fitted a set of Samcos and stainless clips recently. They were water-tight for a few weeks, but after around 300 miles I noticed a few drips of coolant under the car.
Just about all the clips needed "Nipping up", so your leak may be to do with the properties of the Samcos or the clips.

[John_W]

When I fitted my Samcos, some of them took three goes to make water-tight.

[stevebow]

Is it possible to over tighten them.

I'll try bleading the rad as well.

[stevebow]

Though I'd got this fixed after a drive no leaks and levels were good, but no on the next drive to work there is a puddle more tightening needed.

[Simon_P]

A property of rubber is "Compression Stress Relaxation" - You do the clamp up, the stress relaxes over time and the clamp appears loose, you do it up some more , it relaxes and it is a little less loose.

With an OEM application you do it up to a specified torque that allows for the relaxation which is all designed into the clamp, the hose and the spigot.

You could ask Samco since they supplied the clamps and the hoses. Alternatively keep tweaking a little occasionally until the leaks stop.

Read up on the processes for bleeding the system, including warming up until the thermostat opens with the header tank cap off - It is a well documented method but there is potential to boil the coolant if you don't know what you are doing.

[lotusflasherman]

A property of rubber is "Compression Stress Relaxation" - You do the clamp up, the stress relaxes over time and the clamp appears loose, you do it up some more , it relaxes and it is a little less loose.

and silicon is worse. That's why these are used in place of jubilee clips by a lot of manufacturers ..

clip.JPG

it's not that they are just quicker to fit on assembly lines but are 'self adjusting'..

Jubilee clip torque figures are here for anybody who still likes screwing things .. jubilee clips torque

[Fredjohn]

Just to clarify Samco hoses are silicon. I suggest you use the stainless clips that Samco themselves supply.

I did and have had no (noticeable) leaks in over 2 years.

[lotusflasherman]

Just to clarify Samco hoses are silicon. I suggest you use the stainless clips that Samco themselves supply.

I did and have had no (noticeable) leaks in over 2 years.

It's an old chestnut ...https://www.lotus7.club/forum/techtalk/torque-settings-jubilee-clips

[Heavilyass]

This is by far the least pleasant thing that can happen in the car. We went to Spain last summer and rented a car, and the AC was leaking. It’s good that we reported it immediately and that we haven’t been charged for its reparation. But it was honestly horrible as Spain is so hot, and driving without air-conditioning sucks. As for UK we mainly use this company:https://www.spartamech.co.uk/ Don’t know why but we haven't changed them in a while. There might be other suppliers but I'm not aware of their pricing policy.