Non Existent coolant pressure???

[whitespider]

Ok have a spooky recurring problem. I have Very soft coolant hoses.

I have no or little pressure in the coolant system, after a 20 mile run I could remove the rad cap with engine still running with no overflow. Could see coolant in rad cap. No leaks visible, no smoke at the rear, expansion tank a bit fuller than usual but not radical. Soft hoses, and heaters working fine.

Recently changed rad but this problem has been on going on old rad and new one(recon).
Had new head fitted 6 months ago and new water pump two months ago.

Any ideas as this is baffling me?

thanks
Ronnie

[TonyN]

Usually the rad cap, but pump could be on its last legs.

[NiftyNev]

Sounds like radiator cap is not holding presure.May be bottom seal or just passed its use by date.They are cheap enough so just replace it.

Neville

[Guest]

I'd agree with Neville, system should pressurise even with the pump not working properly (unless the bearings and seals have gone allowing pressure to release in which case you would probably see a leak from the bottom of the timing belt cover). My bet would be rad cap. Put a 1.1 bar one on as the system should stand the higher pressure and more pressure means a high boiling point.

Cheers

[NiftyNev]

One more thing.After you replace the cap keep an eye on cooling system for a couple of days.If previous cap was faulty and new cap now pressurising cooling system any other leaks or faults in cooling system should be obvious.

Neville