Air Compressor Desicant

[101RRS]

I have a bag of air compressor desiccant that has been sitting on the shelf for a few years in its zip loc bag. The colour has changed from orange to brown so may have absorbed a little moisture through the bag over the years. As it has not changed to blue or white it should still be OK to use but to make sure I want to cook it in the oven a bit to remove any moisture it has absorbed.

So what temperature does the oven have to be and how long do you cook it it for? Time or when the beads change back to orange?

Thanks

Garry

[Grappler]

150 C for 40min in convection oven

You could google microwave regeneration of silica gel dessicant.

In a lab they would heat it and cool it in a dessicator and weigh repeatedly till it didnt loose mass to prove it 100% dry

[101RRS]

Thanks - that is great.

garry

[101RRS]

Cooked the desicant - some beads were still blue after the 40 min so going for 60 min.

Next question - I have an exhaust valve kit to go into the Hitachi compressor however I cannot remove the big nut (17mm) without damaging it. Is there a way to remove the exhaust valve without wrecking it.

148898

thanks

Garry

[Grappler]

Is the exhaust valve buggered? Assuming the compressor is pumping OK, it makes a farty sound within a minute of starting the engine if its working OK
I bought the upgraded kit from 4x4 airseals to include the exhhaust valve kit
It came with a printed leaflet advising not to use the kit unless the old valve had failed. The risk of damage outweighs a routine valve changeout and the exhaust valves rarely fail
I took the advise and the original valve continues to work a year or so after the rebuild.

[101RRS]

I have no idea if the exhaust valve is working or not(I assume it still is). Advice from a few different places was to put a kit in it when working on the compressor so i bought the kit after all it is just a O ring, spring and seal moulding. I wasn't expecting the force required to move the housing - if I apply more force it will wreck it so I am having to go with the exhaust valve I have.

Thanks for the input.

Garry

[101RRS]

Some for information from the learned compressor gurus?

I assume this is the valve that opens and closes as the piston goes up and down in the attached pic.

Can someone confirm it is the right way around?

148899

Also - if a AMK was to be fitted in place of the Hitachi the AMK will actually run without without its software upgrade but I understand the software patch is to lower its pressure.

Now I have heard there is actually a software update for the Hitachi that does a similar process - can anyone confirm?

Thanks

Garry

[Eric SDV6SE]

Cooked the desicant - some beads were still blue after the 40 min so going for 60 min.

Next question - I have an exhaust valve kit to go into the Hitachi compressor however I cannot remove the big nut (17mm) without damaging it. Is there a way to remove the exhaust valve without wrecking it.

148898

thanks

Garry

As per other posts “if it ain’t broke....”

However, were you able to get the other bolts holding the exhaust valve off? Your pic shows the arrow to the lower left one. Try some Penatrene, or WD 40. Personally I’ve found the WD lawnmower cleaner work very well on corroded and especially alloys in freeing up bolts.

seems a bit odd that they offer a valve kit for the exhaust, then recommend not to service it.

[101RRS]

As per other posts “if it ain’t broke....”

Your pic shows the arrow to the lower left one. (I dont have photoshop and Paint does not do good arrows [wink11])

No is pointed to the large 17mm head of the actual exhaust valve - it will not move so I am not going to tempt fate.

I certainly accept the advice that Grappler provided about not servicing the exhaust valve but that is not consistent with many other posts on various LR forums. There were no instructions whatsover for my kit. If the exhaust valve was easy to undo I would replace it but as it will not undo without damage it is staying where it is.

Cheers

garry

[Eric SDV6SE]

No is pointed to the large 17mm head of the actual exhaust valve - it will not move so I am not going to tempt fate.

I certainly accept the advice that Grappler provided about not servicing the exhaust valve but that is not consistent with many other posts on various LR forums. There were no instructions whatsover for my kit. If the exhaust valve was easy to undo I would replace it but as it will not undo without damage it is staying where it is.

Cheers

garry
No worries Garry, likewise I wouldn’t be tempting fate either if that is not moving.

[Red90]

What are you using to turn it that is damaging it?

[101RRS]

What are you using to turn it that is damaging it? A 6 sided 17mm socket - it is all crap cast metal so cannot handle much torque before starting to deform.

[Red90]

Maybe get a decent socket set? A socket should never deform the head of the fastener.

[101RRS]

Maybe get a decent socket set? A cocker should never deform the head of the fastener.

Hmmm it is a decent socket set.

[101RRS]

Ok - couldn't leave well enough alone [bighmmm].

Result:
148915
The head of the exhaust valve.

148916

The remainder of the exhaust valve.

Is is locked in there rock solid.

Garry

[BradC]

Ok - couldn't leave well enough alone [bighmmm].

Is is locked in there rock solid.

If it hasn't moved, you might just get away with leaving it as it is.

[101RRS]

I bought the upgraded kit from 4x4 airseals to include the exhhaust valve kit
It came with a printed leaflet advising not to use the kit unless the old valve had failed. The risk of damage outweighs a routine valve changeout and the exhaust valves rarely fail


My experience today shows why it may not be a good move to play with the exhaust valve - however this is the one area of the compressor that is prone to internal corrosion. I googled this and it is clearly a major issue with these compressors, time and time again I found instances where the pics were almost exactly the same as mine.

When air goes through the desiccant it is dehumidified and then into the suspension system. To get rid of the moisture in the desiccant when the system is lowered or needs to loose pressure the "dry" air goes back into the desiccant chamber collects some of the moisture from the beads heads and around the closed exhaust valve and out the exhaust port - so in the area around the top of the piston head is constantly in humid air - hence the corrosion problem that I experienced today - also the exhaust valve can stick open ever so slightly with the corrosion leaking air out internally to the exhaust port so making the compressor work harder to get to the required pressure.

So on one hand there is a danger in checking the exhaust valve but on the other it could be leaking air and you may not know it.

Garry

[101RRS]

If it hasn't moved, you might just get away with leaving it as it is.

No, it is leaking air when the compressor is running.

[BradC]

No, it is leaking air when the compressor is running.

Bugger. My next move would require access to a mill and some fairly concentrated nitric acid. Might be easier to replace it.

[Blknight.aus]

Bugger. My next move would require access to a mill and some fairly concentrated nitric acid. Might be easier to replace it.

well, I happen to know a guy whom if you get the compressor down to say, eltham has the gear to do that.

if you're not in a hurry, a detour on his way home from ironfest would get it back to your place in canberra.

[101RRS]

Bugger. My next move would require access to a mill and some fairly concentrated nitric acid. Might be easier to replace it.

A temporary fix with superglue has sealed it up and I will order a new exhaust valve housing. I will drill that plug out and put the new housing in with some neverseize on the threads.

[Eric SDV6SE]

Perhaps a silly question, but it's not a left hand thread is it?

Apologies in advance for any offence caused

[101RRS]

No it is a right hand thread.