HYDROLASTIC SCHRADER VALVE

[jl46]

Hello All,
We are finishing up the installation of the hydrolastic system on a 1966 MCS.

We have tested the system with air. It seems to have a small leak as the suspension will drop
after a few days. We replaced the Schrader Valve in part# 13H1705 with a "standard" shrader valve
as used with tires. No change....still have small leak.

Questions:
Is there a "special" sharader valve that needs to be used in 13H1705 ?
If so, who might sell them ?
Do we need to replace the whole Hydrolastic Bleed Valve assembly, part # 13H1705 ?
Any other ideas ?

Thanks,
Jim

[LDR209H]

Why are you convinced it's the valve ? I'd pump it up with fluid,then you'll see the leak ! Most likely a union or displacer flexible.

[Daz1968]

A bit of soapy water will test the valve as well, you could then go over the joints with it as well if you wanted. But easiest way is to just pull the vacuum in the system and fill with fluid.

[Spider]

The Valves are the same ones used in tyres.

But, as the other guys have said, fill it with fluid, you may in fact find it doesn't leak, but if it does, it will be easy to find.

[minicentie]

The system is build to work with pressure,not vacuum.
The only reason it needs to be vacumed is to leave as little air in as possible,because it could rust from inside.
So pressure the system and look after a copple of days f the car is still square on it's feet.
Do not try to check the pressure again,because you will let a little bit of pressure bleed out every time. And you will think it has lost ,but acctually it didn't; You did.
The pump is not perfect,we had to rebuild and tune it to work beter than ever (churcill pump) .

[66S]

The valve is the same one used in tractor tyres that have water added as traction ballast. Talk to a tractor shop or a rural tyre outfit that repairs tractor tyres.

Regards
Al

[andy1071]

The Schrader valve is only there to allow you to pressurise the system (be it hydrolastic suspension or a tyre).
It is not a reliable seal.
-The cap is the seal!
-Look inside a metal cap and you'll see the seal....

[66S]

The Schrader valve is only there to allow you to pressurise the system (be it hydrolastic suspension or a tyre). ...

Andy,
I totally disagree with that. The valve cap (or dust cap) is there to stop dust entering the valve core seat and ruining the seal. A valve cap will not prevent a valve core leak.

Regards
Al

[andy1071]

The valve is not a reliable seal.
They are subjected to high G forces and bumps when used on a wheel.
They do move and leak.
- This is information I have received from tyre companies, when working with them during vehicle testing/development.

I would not run a vehicle without caps, but if anyone wants to, that's fine with me. I come only share the information.

[66S]

I spent many years with tractors, on our farm and later when I served my Diesel Engineering Apprenticeship. Schrader water valve cores are not prone to leaking and unlike air, it is pretty easy to spot if they do. I'll leave it at that.

Regards
Al

[rogerotto66s]

Just pumped up the LH side of my 1966 “S” with no leaks!
I used my grease gun set-up

89699687-F67A-4366-876A-C5D1FEA74AF0.jpeg

When I disconnected my grease gun from the RH side the liquid ran out through the shrader valve - 13H1705 (much to my surprise). Seems the valve core was not properly seated. I purchase a tool and was able to tighten the valve core. Re-pumped the system and all is OK now.

Here is my shrader valve, valve core and the tool I purchased.

11CCCBE3-9C75-4101-9894-71210B5C118A.jpeg

The tool has these 4 functions - remove valve core, re-tap threads inside, re-tap threads outside and ream inside valve.



Both a local farm/tractor supply and industrial fittings supply were unable to provide a replacement shrader valve which fit the Hydrolastic elbow. This surprised both of them! Perhaps reading is different.

Also purchased a package of valve cores and was surprised to see they were quite different from the one in the above picture.

So ... it appears shrader valves are not universally the same.

I was able to purchase a used “mini” shrader valve from my “go to” mini supplier.

I am now looking for a single “metal” cap for one of my shrader valves. Does anyone have an extra?

[Peter Laidler]

I've made hydrolastic a bit of a pet hate subject. Agree with Rogerotto (above) entirely. I've only ever used a grease-gun type pump and have it down to a fine art. Leaky valves......., what's the problem? Just go to your local Tesco or chemist and buy a small pack of INTERDENTAL brushes. The sort that you brush between your teeth with. There's a few different shapes, colours and harshness. Remove the valve cores and scrub out the valve housing. Insert new standard car tyre valve. Tighten up as per Roger and they'll be fine.

The hydro system might be crap....., a frill if not a direct fraud (only my opinion of course.......) but the schrader valves are as good as it gets and have been since we started pumping air into tyres