P38A A couple of queries about rebuild EAS valve block

I'm just about to re-build my EAS valve block.
A couple of queries however that came to mind as I was removing it form the car and wouldn't mind getting a second opinion on.

First, I'm rebuilding it as my tank slowly looses pressure (circa 2 psi per hour) and it;s not from the tank or the line going to the tank as I tested them in isolation.

First thing I noticed is the pressure relief valve threads have a load of silicone on it.
It's not a bit I can access when on the car, so I guess this could have been the source of my problem.
I wasn't going to remove it, but now I need to find a way to test it's sealed.
All I have to hand is a 6mm shader valve and some 6mm pipe.
How can I test the thread here whilst being the least amount of kit?
And why would threads leak such that someone needs to use silicone? Stripped perhaps? If so, am I better looking for another block first? Anybody selling one cheap?


Side note, this block has been beautifully machined. Great work Land Rover. Probably a bit over the top, but I like it.

Back to problems.
The hole to the left is where the pressure senor was. It has some hard white crud around the hole and on the threads. What is this? Do I need a special sealant here?
I know others have just used some loctite to seal. Is this adequate?

Finally, I'm umming and ahhring what to do with the pipes.
They were sealing fine prior to removal, but they don't look in great condition. I was careful removing, using a plastic chopstick to press the collet.
I would trim back, but they get worse before they get better.
Would some silicon grease or similar help just to give the pipes the best chance of sealing?

Hi there,
If you're concerned about those pipes, I'd get some new pipe & cut those ends off and inline join it with the relevant fittings..
I've got a couple of spare valve blocks knocking around, but where in the UK are you.. I'm near to Stafford..?
Titch

1) For the pressure relief valve, use Loktite 577. (I have used it on loads of NPT & BSF pipe fitting with zero leaks.) The relief valve is only under pressue when the pump is on, so if it's leaking it will increase the tank fill time, but not cause tank leaks. Once the pump stops, NRV-1 should hold the tank pressure, so check that first. Same sealant for the pressure switch threads.

2) For the airlines as they were previously sealing ok, smooth off any bumps, and use new o-rings (two per port). I generally lubricate with spit when inserting them. Make sure you feel the pipe go into both o-rings.

3) For the NRV's, examine them closely, and select the one with best cone condition for NRV-1. Use new Black Nitrile o-rings on all three.

4) Tank leak can also be via the Inlet Valve, so make sure that seals properly. (When system is off & tank is pressurised, then NRV-1 should hold shut, but NRV-2 is open, so Inlet Valve has to hold the tank pressure)


Here's the diagram so you can see where the air goes:


3)

PTFE tape is what I use for the pressure sensor and relief valve threads. The white crud is likely to be from the desiccant in the dryer breaking up.

TITCH SANDERS said:

Hi there,
If you're concerned about those pipes, I'd get some new pipe & cut those ends off and inline join it with the relevant fittings..
I've got a couple of spare valve blocks knocking around, but where in the UK are you.. I'm near to Stafford..?
Titch

Click to expand...

I'm in South London so not convenient. I'll remove the pressure relief valve tonight and see what things look like.
With the pipes, I'd rather avoid adding any new points of failure. I've read that the plastic push units don't like the exhaust headers being so close.

That diagram is great.

Lips on the tank outlet port (6, but looks like an 8), blowing hard, with my finger on the covering the pressure switch hole (12), I can hear air coming out of the dryer inlet port (5, but looks like a 6), so NRV-1 must be leaking.

Looking forward to seeing why it's failed and how.

Datatek said:

PTFE tape is what I use for the pressure sensor and relief valve threads. The white crud is likely to be from the desiccant in the dryer breaking up.

Click to expand...

Just cleaning off the crud now, it feels like body filler that doesn't have any hardener in it. So I'm guessing some sort of sealant. Going to clean it all off and start again. If it's compromised in anyway, I'll start with another block.

Montyjohn said:

Just cleaning off the crud now, it feels like body filler that doesn't have any hardener in it. So I'm guessing some sort of sealant. Going to clean it all off and start again. If it's compromised in anyway, I'll start with another block.

Click to expand...

If it is silica gel from the from dryer, you will find more of it in the block. In any case the dryer should IMO be replaced if it has not been changed recently.
Mark the solenoids as you remove them from the block, easy to transpose them on reassembly.
With everything removed, the block can be put in the dishwasher to clean it if contaminated with white powder.

Montyjohn said:

With the pipes, I'd rather avoid adding any new points of failure.

Click to expand...

I agree.
New pipes arent too bad. Trick is to attach the new pipes to the old disconnected ones, so as you pull the old out the new slides in. If you get any serious issues regarding the block @kurtjohnson10 is the guy to see, presuming he is still rocking.