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Randy Roberson
Prolific User
Username: wascator

Post Number: 300
Registered: 5-2009
Posted on Sunday, 07 September, 2014 - 08:37 am:   Edit PostDelete PostView Post/Check IP

Hi, In rebuilding Her brake pumps, and by means of general refurbishment, I removed and reworked the header tank. I installed a new cap rubber seal, and the cap is not chipped in the critical surface. I can blow on the overflow hose and hear air leaking from the cap (confirmed using soapy water). I got it about as tight as I could by hand; how tight should it be? I can seal the opening with my palm and no leak, and it will build some pressure when I blow on the overflow hose, and hold it until I release it.
I don't know what else I can do. I have no idea if it was sealing before this work, because the steam valve was shot and there was no pressure on the cooling system at any time during my time with the Car.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1252
Registered: 6-2006
Posted on Sunday, 07 September, 2014 - 08:51 am:   Edit PostDelete PostView Post/Check IP

I can blow on the overflow hose and hear air leaking from the cap (confirmed using soapy water). I got it about as tight as I could by hand; how tight should it be? I can seal the opening with my palm and no leak, and it will build some pressure when I blow on the overflow hose, and hold it until I release it.

The overflow pipe is not within the pressurised side of the cooling system.

It allows the steam valve to vent to the atmosphere. I think you will find it should also allow any overflow from the cap to run down to the floor, I think there should be a hole at the bottom of the cap threads on the outside of the pressure seal.
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Randy Roberson
Grand Master
Username: wascator

Post Number: 301
Registered: 5-2009
Posted on Sunday, 07 September, 2014 - 09:02 am:   Edit PostDelete PostView Post/Check IP

Excellent point that I missed, Paul. You are of course right about the overflow hose. I remember that the steam valve will hold pressure on the system, but not vacuum; therefore I can blow air into the tank and it will hold it as long as it is not leaking anywhere else (like at the filler neck).
I will look more closely at the filler neck area. I may have to remove the tank and "go in", or else I can buy a tested used one from Flying Spares.
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Randy Roberson
Grand Master
Username: wascator

Post Number: 302
Registered: 5-2009
Posted on Sunday, 07 September, 2014 - 12:08 pm:   Edit PostDelete PostView Post/Check IP

UPDATE: I removed most of the coolant from the tank. In looking/feeling around the neck of the tank, above the rubber seal, I felt an opening; a mirror revealed a hole, approx. 3/16 inch diameter, in the neck above the rubber seal, and below the threaded portion of the neck.
This is not a flaw nor a corroded hole, it is a hole made there for a reason. What is the reason, and why is it letting my tank leak past the rubber cap seal?
I am purely guessing here: is it a drain, in case of overfilling the tank, to lead the excess out so it does not spill over when the cap is replaced? If so, it must have an internal tube to keep it separated from the tank, and maybe this tube is broken or corroded.

JUST GOT IT: It is a drain and it connects to the steam valve dump, which I was blowing on. The tank in fact is NOT leaking.
Amazing!
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Bob uk
Unregistered guest
Posted From: 94.197.122.90
Posted on Sunday, 07 September, 2014 - 10:12 am:   Edit PostDelete PostView Post/Check IP

I checked my header tank by filly with water and fitting a piece of hose with a tireless tyre complete Schrader valve held in the hose with super glue and a hose clip. And pressurized the tank to the book pressure.

It worked fine so I painted it gloss black. I removed the label first.

I shouldn't think a new tank is necessary. If it wasn't leaking and you put a new steam valve then it should be fine.

At first sight the overflow arrangement is not obvious.

The tanks can be repaired by using normal rad repair technics.

I love the idea that my car has a steam valve. Not a radiator pressure relief valve. Instead of a temperature gauge I could have a steam pressure gauge.

(Message approved by david_gore)
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David Gore
Moderator
Username: david_gore

Post Number: 1460
Registered: 4-2003
Posted on Sunday, 07 September, 2014 - 04:47 pm:   Edit PostDelete PostView Post/Check IP

"I love the idea that my car has a steam valve. Not a radiator pressure relief valve. Instead of a temperature gauge I could have a steam pressure gauge."

Bob, now you are speaking the right language......

Have spent more time than I care to admit speculating how Sir Henry would have designed a steam engined electric motor driven vehicle derived from the steam cars engineered by the Stanley twin brothers and his electric motor experience from building cranes instead of a car driven by an internal combustion engine.

Perhaps the fuel cell electric car would have appeared much earlier than it has...............
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1253
Registered: 6-2006
Posted on Sunday, 07 September, 2014 - 07:58 pm:   Edit PostDelete PostView Post/Check IP

That saved some work :-)

I might add at this point that:

If your a RR or B is leaking up through the cap threads (especially on clouds) and running across the header tank, then chances are the overflow hose has collapsed inside or blocked and not allowing fluid through.

Not too much of a problem - but if in conjunction with a not so good cap seal, it will then leak water over the tank to the seams and collect there. It will dry quickly on the tank but sit in the seam well giving the impression that the seam is leaking. Easy for us to spot with the correct cooling system pressure gauge, but owners have been convinced it was a much bigger problem than it acyually was.
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Bob Reynolds
Prolific User
Username: bobreynolds

Post Number: 152
Registered: 8-2012
Posted on Sunday, 07 September, 2014 - 10:23 pm:   Edit PostDelete PostView Post/Check IP

"I may have to remove the tank and "go in", or else I can buy a tested used one from Flying Spares."

I went to FS to swap my header tank because the internal baffle had come loose and rattled about. The first question he asked me was 'Does it rattle?'. I had to admit that it did. He said 'They all do!' Apparently they are only spot-welded in position and the welds corrode away.

He said that he could change it for a second-hand one, but that would probably rattle as well and be no better than the one I had! He did actually find one that didn't rattle, but that turned out to be from a Cloud, so no good to me. They had no reconditioned ones in stock.

I had to bring my old one back and try and fix the baffle somehow because it was moving about and hitting the coolant probes, shorting them out and ultimately bending and breaking them.

I wonder if anybody else has had this baffling problem, and how they fixed the baffle in position. You probably won't realise the baffle is loose unless you either remove the tank (when it becomes obvious) or prod it with your finger through the top of the tank to see if it's loose.

This experience made me realise that buying second-hand parts can be risky, as they may be no better than the part you already have.
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1254
Registered: 6-2006
Posted on Sunday, 07 September, 2014 - 11:29 pm:   Edit PostDelete PostView Post/Check IP

I wonder if anybody else has had this baffling problem, and how they fixed the baffle in position.

Most radiator repair shops would only need if foe a couple of days if you book it in in advance.

Get it reconditioned or buy a reconditioned one.

Unless you have the equipment and you are good at it, it's not a diy job.
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Randy Roberson
Grand Master
Username: wascator

Post Number: 303
Registered: 5-2009
Posted on Sunday, 07 September, 2014 - 11:45 pm:   Edit PostDelete PostView Post/Check IP

Well, I was baffled for a bit, but with a little guidance I got on the right track and in fact did not have a problem.
For once.
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Bob uk
Unregistered guest
Posted From: 94.197.122.84
Posted on Monday, 08 September, 2014 - 12:20 am:   Edit PostDelete PostView Post/Check IP

All's well that ends well.

If a whistle was fitted to the steam valve then-----.}

(Message approved by david_gore)
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Benoit Leus
Prolific User
Username: benoitleus

Post Number: 169
Registered: 6-2009
Posted on Monday, 08 September, 2014 - 05:55 pm:   Edit PostDelete PostView Post/Check IP

I had the same problem when I replaced my header tank.
There was coolant leaking from the filler cap, although it had a new seal and the steam valve had been replaced too.
In the end I glued two cap seals together and it has been fine ever since. It just seemed that the old cap didn't fit the new header tank well enough.

Benoit
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Bob uk
Unregistered guest
Posted From: 94.197.122.93
Posted on Tuesday, 09 September, 2014 - 05:24 am:   Edit PostDelete PostView Post/Check IP

Unfortunately the standard rad pressure pump does not fit a RR

Which why I made up the Schrader valve in a hose what's it.

The gadget I made is not very good because the valve to hose connection is sh#t.

A better way would be a copper tee piece with the valve in the tee and a short hose on a leg of the tee. Fit the short hose to the head tank and the remaining leg of tee plug into the pipe that goes to the head tank.

Pump up to 2psi. Check then go to blow off pressure on the steam valve. Important don't put air in fast. My trye gauge needle starts to move at 2 psi. Then I stop and see if the gauge holds. With the hand pump type it's much safer because you can feel the pressure. Whereas if one was to just pump air in Willy nilly then it could blow a hose off.

I did this on a mini and the heater pipe inside the car blew off and made a right mess of rusty water. Fortunately no anti freeze. That's the way to turn a 5 min job into a couple of hours.

What sort of pressure tester does a RR service garage use?

(Message approved by david_gore)
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Paul Yorke
Grand Master
Username: paul_yorke

Post Number: 1258
Registered: 6-2006
Posted on Tuesday, 09 September, 2014 - 08:05 am:   Edit PostDelete PostView Post/Check IP

We use a spare cap which has been drilled through at the bottom of the hex to accept a gauge with a Schrader valve to introduce and release the pressure.

Hand, foot, or cigar lighter type tyre inflater pump. Never an air line :/ . You do not need a high volume of air and definitely don't need a high pressure.
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Bob uk
Unregistered guest
Posted From: 94.197.122.75
Posted on Tuesday, 09 September, 2014 - 10:18 am:   Edit PostDelete PostView Post/Check IP

I did the same thing with a ac regular type radiator cap. It worked well but I lost it some where. I wondered if there was a special RR adaptor for the ac pressure tester. Which I have. If I come across a spare cap then I shall make one. I did think of a permanent air valve, but the system is reliable and fitting a temporary valve is merely 2 mins work and an air valve introduces a untested failure point and extra engine clutter.

A push bike pump will do fine.

I use a tyre gauge and give a quick on off.

As you say with water in the system not a lot of air is required. So one must be careful in case the radiator bursts or something happens to the water valve diaphragm. Or even worse the heater radiator.

Hopefully the steam valve will lift before damaging anything.

But I suppose the steam valve could jam shut which is part of the test. So one must be careful with compressed air. If you are windy ( pun intended) then a push bike pump. Not from the 99 p shop because they don't seem to work.


I was once leaning over a xk engine and a hose blew and I got covered is hot antifreeze. Fortunately I had a leather jacket on and manage to twist back and got away with it. There was antifreeze dripping off the roof.

Note to anybody reading this who has not used compressed air.
Compressed air over say 5 psi is dangerous and 30psi is very dangerous. So when it gets to shop pressures of 80 psi to 120 psi I am extremely cautious with air pipes etc. All my hoses etc have swaged hose clamps and are bright yellow (trip hazard) also I drain regular and use only properly maintained compressors. With a proper pressure vessel cert. Anything wrong I pull the fuse. My air gun for blowing stuff has a safety nozzle. I never plug open connectors into the air socket. I have two circuits one is oil free and the other has oil mist for air motors in air tools.
Also the compressor must be kept clean because a load muck can over heat them. All any air leaks will cost electricty and you will be surprised how much. My system holds pressure for approximately 6 hours before the compressor kicks in.

Whereas my mate's Ingersoll rand cuts in every 30 minutes every thing he plugs in whistles from connectors because he to tight to by new ones. Because of the leaks I have more capacity on a smaller cheaper compressor.

For those that who know the above don't forget.

(Message approved by david_gore)

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