Rad cap

[MattF]

Opinions please. Anybody ever had a rad cap top seal cause problems,
allowing some minor coolant loss through the cap itself, even though the
seal appears intact? Still got a minor leak from somewhere. No discolouration
on the brass senders, so ruling those out. Sealed top hose with hermatite red
at both ends the other week, and the brass section in the top hose is 38mm,
so the hose is a snug fit on that. Also nipped up all the jubilee's. Still slight
dampness on thermostat housing, and splatter on that side of the engine,
however. So, what are the chances of it being knacked rad cap under certain
conditions?

[TonyN]

Opinions please. Anybody ever had a rad cap top seal cause problems,

Quite often, and with new caps! They can leak around the main seal so it looses water when its filling the expansion tank, or the small seal so the expansion tank fills up all the time.

[MattF]

Quite often, and with new caps! They can leak around the main seal so it looses water when its filling the expansion tank, or the small seal so the expansion tank fills up all the time.

Cheers Tony. I've triple checked, tightened and sealed everything else,
all new hoses as well, so I'll try the cap. It's a devil trying to find the leak
when you can see splatter, but it'll never leak unless it's under some certain
type of running condition. I used genuine Toyota cap last time. Are they
still the best one to use, or is there a more sturdy aftermarket brand?

[BUSHWHACKER]

Cheers Tony. I've triple checked, tightened and sealed everything else,
all new hoses as well, so I'll try the cap. It's a devil trying to find the leak
when you can see splatter, but it'll never leak unless it's under some certain
type of running condition. I used genuine Toyota cap last time. Are they
still the best one to use, or is there a more sturdy aftermarket brand?

My week old rad cap was allowing coolant past so I made a thicker gasket/sealing ring from some rubber sheet I had lying around. No worries since.



Want me to make and mail you one Matt?

[MattF]

My week old rad cap was allowing coolant past so I made a thicker gasket/sealing ring from some rubber sheet I had lying around. No worries since.



Want me to make and mail you one Matt?

I'll take you up on that offer, Vince. Any chance you might be able to do
a top and bottom seal? If it is the rad cap at fault, mine is probably the top
seal causing the main problem, rather than the bottom one, which I think is
the one you had trouble with? I know I was looking for some rubber sheet a
while since for doing something, and I have nowt like that here. Let me
know what you want for 'em. Cheers.

[BUSHWHACKER]

I'll take you up on that offer, Vince. Any chance you might be able to do
a top and bottom seal? If it is the rad cap at fault, mine is probably the top
seal causing the main problem, rather than the bottom one, which I think is
the one you had trouble with? I know I was looking for some rubber sheet a
while since for doing something, and I have nowt like that here. Let me
know what you want for 'em. Cheers.

It's the rubber gasket that seals against the neck of the thermostat housing that I replaced, the one directly under the cap.
All I need is your address mate!

[MattF]

It's the rubber gasket that seals against the neck of the thermostat housing that I replaced, the one directly under the cap.
All I need is your address mate!

Cheers Vince. I'll drop you a P.M.

[MattF]

It's a good job I have a mix of persistence and patience. Found where
that specific leak was coming from, (the top hose to thermostat housing
joint again), so nipped that clip up, again. Since then, water going into
expansion tank okay, bugger all being drawn back in when it cools down.
Tried another rad cap that I picked up from a local factors, no change.
Rechecked all hoses again today, looks like the turbo dog leg hose is the
culprit this time. Nipped that up earlier, so have to check tomorrow to see
if it's sucking coolant back in instead of air now. Which does lead to one
other minor question. Is there a maximum amount you should tighten up a
hose when using Jubilee clips? Or is it okay to keep nipping up until the leak
stops, even if the clip is bedding well down into the hose wall?

[TonyN]

You can overtighten the clip and damage the hose, more likely the fitting is rough and corroded, so it hard to seal.

It shouldn't be that hard to seal with a good hose and right size clip.

Sometimes the inner part of the hose can degrade, and fluid leaks along the reinforcing strands and out the end, then you have trouble getting the clip to seal it.

[MattF]

You can overtighten the clip and damage the hose, more likely the fitting is rough and corroded, so it hard to seal.

It shouldn't be that hard to seal with a good hose and right size clip.

The main culprits seem to be the turbo coolant pipes and the top hose. I
cleaned all the crud and scale/rust off the pipes when I renewed all the
hoses, so I may have acually shot myself in the foot there. Generally
I tighten the clips up until the metal is roughly flush with the hose surface,
but some have needed nipping up far tighter than that.

Sometimes the inner part of the hose can degrade, and fluid leaks along the reinforcing strands and out the end, then you have trouble getting the clip to seal it.

Hopefully I should be okay on that point. Apart from the lower rad hose and
matrix hoses, all the other hoses were replaced with new hose a few months
ago.

[NiftyNev]

I don't know if you guys have this stuff over there but it's great if you can get it. Down here it's called Loctite (Once permatex) Aviation Form-A-Gasket. It's a thick dark brown liguid and excellent for radiator hoses and fittings. Brush a thin coating on fitting and inside hose and then assemble. I've used it for many years. It also helps stop corrosion on pipes and fittings.

Nev

[MattF]

Cheers for that Nev. Not managed to find a supplier yet, but with it
being Loctite, it should be available over here somewhere. If my luck
with these hoses carries on like it is, I'll probably be whipping them
all back off and sealing and refitting them.

[MattF]

Would anybody happen to know where you can get that stuff, or something
like, over here? I'm drawing a blank at the moment. Things still not going to
plan, so I might as well start from scratch again.

Been nipping up again today, , and this time it's decided to pop a leak
on that inline switch housing in the top hose that I made. Soooo,
what would be the general thoughts, (bad idea or not), of putting the old top
hose back on, making the auxilliary rad fan completely manual switched, and
nicking it's temp switch spot on the thermo' housing for the main rad fan
switch? Cheers.