Expansion tank cap woes.

[mcapinha]

After my recent problem with the expansion tank filled with some kind of goo (http://www.landyzone.co.uk/lz/f10/expansion-tank-cap-full-gunk-158412.html), I decided to add a new tank cap to a order I had planned from Island 4x4.
The cap I received came in a Britpart bag and had no indication of it's manufacturer. It looks identic to my old cap with the exception that the valve (marked 140) is yellow in the Britpart one and red on my older cap.

So, I replaced my old cap with the new one and drove around 300km when the engine temperature started to rise just above 12 o-clock. After a while it started raising more quickly and I let go of the gas and drove slowly to the first service stop. Plugged my Hawkeye and read that the engine was over 100ºC and while idling the temperature started to raise once again (going over 12'o-clock and reading over 100ºC). Stopped the vehicle and very carefully took the cap off. Exchanged it with my older cap and drove without a single problem for the next 100km. Hawkeye plugged in all the way and the temperature of the engine never went above 95ºC.

So, which cap is at fault ? Was my old cap broken and masking a problem or is the new Britcrap cap the culprit ?

 

[wammers]

After my recent problem with the expansion tank filled with some kind of goo (http://www.landyzone.co.uk/lz/f10/expansion-tank-cap-full-gunk-158412.html), I decided to add a new tank cap to a order I had planned from Island 4x4.
The cap I received came in a Britpart bag and had no indication of it's manufacturer. It looks identic to my old cap with the exception that the valve (marked 140) is yellow in the Britpart one and red on my older cap.

So, I replaced my old cap with the new one and drove around 300km when the engine temperature started to rise just above 12 o-clock. After a while it started raising more quickly and I let go of the gas and drove slowly to the first service stop. Plugged my Hawkeye and read that the engine was over 100ºC and while idling the temperature started to raise once again (going over 12'o-clock and reading over 100ºC). Stopped the vehicle and very carefully took the cap off. Exchanged it with my older cap and drove without a single problem for the next 100km. Hawkeye plugged in all the way and the temperature of the engine never went above 95ºC.

So, which cap is at fault ? Was my old cap broken and masking a problem or is the new Britcrap cap the culprit ?

Did you lose any coolant in this process?

 

[mcapinha]

Did you lose any coolant in this process?

Yes and it looked like that some of it had come out through the cap's screw (and some had come out through the discharge pipe).

 

[Datatek]

Yes and it looked like that some of it had come out through the cap's screw (and some had come out through the discharge pipe).

Maybe it was just not screwed down tight, mine is very hard to turn the last 2 turns.

 

[wammers]

Yes and it looked like that some of it had come out through the cap's screw (and some had come out through the discharge pipe).

Right that is what i needed to know. Cap is a simple unit that allows a certain pressure to build within the system and release excess pressure. 15 psi is the setting for your cap, each pound of pressure raises the boiling point of the coolant by 2 degrees F. So instead of boiling at 212 F it boils at 242 degrees F. If the cap is not sealed properly and there is no pressure or lets pressure off below 15 psi. Coolant will be vented and the temp will rise. I would say either you did not tighten your new cap down properly or it is duff. Also that your old cap is sound.

 

[wammers]

Maybe it was just not screwed down tight, mine is very hard to turn the last 2 turns.

Correct Keith, that may well be his problem. Or a duff new cap. The old one seems ok.

 

[Fur Trapper]

Right that is what i needed to know. Cap is a simple unit that allows a certain pressure to build within the system and release excess pressure. 15 psi is the setting for your cap, each pound of pressure raises the boiling point of the coolant by 2 degrees F. So instead of boiling at 212 F it boils at 242 degrees F. If the cap is not sealed properly and there is no pressure or lets pressure off below 15 psi. Coolant will be vented and the temp will rise. I would say either you did not tighten your new cap down properly or it is duff. Also that your old cap is sound.

read where a proper 50/50 mix of antifreeze and h2o will boil at 240-260 degrees f depending on altitude and 95-100c is within operating range of lr specs.
also on the range rover the thermostat is a electric operated not a mechanical operated

and with a new cap put a thin film of oil and the rubber seal will set it self easier when you tighten it and will go on harder when new

 

[wammers]

read where a proper 50/50 mix of antifreeze and h2o will boil at 240-260 degrees f depending on altitude and 95-100c is within operating range of lr specs.
also on the range rover the thermostat is a electric operated not a mechanical operated

and with a new cap put a thin film of oil and the rubber seal will set it self easier when you tighten it and will go on harder when new

If you mean the engine stat John it is a simple waxstat. No electricary involved.

 

[mcapinha]

Here's a pic of the new cap:

Looking carefully at it the second o-ring from the top seems twisted and I'm not surprised that it won't seal properly

 

[Datatek]

A smear of silicone grease helps it seal

Here's a pic of the new cap:

Looking carefully at it the second o-ring from the top seems twisted and I'm not surprised that it won't seal properly

 

[wammers]

O ring is no good put a new one on. Slight smear of silicone grease and slip new one on. Old one looks like it has been assembled dry.

 

[fett]

usual britpart ****e then :doh:

 

[mcapinha]

usual britpart ****e then :doh:

That's exactly where I was going when I started to write this thread. I toned it down a bit after having doubts about the original cap (which I'm now using without any problems).

 

[wammers]

That's exactly where I was going when I started to write this thread. I toned it down a bit after having doubts about the original cap (which I'm now using without any problems).

You could go to Land Rover and get a cap in the same condition. You have been unlucky. LUK are one of the biggest clutch manufacturers and usually good quality, i have had pressure plates with un-heat treated diaphram fingers. **** happens.

 

[mcapinha]

Well, will you agree that the Britpart logo usually favours the possibility of **** happening ?

 

[wammers]

Well, will you agree that the Britpart logo usually favours the possibility of **** happening ?

No more than it does with any other company importing **** from China and India to make a big profit. Car parts can be **** from anybody these days sadly.

 

[fett]

ive been very lucky with allmakes then,doh i shudnt have sed that :doh: