Dodgy schrader valves

[Andy AC]

Has anybody come across problems with dodgy/broken shrader valves on R410a systems? I've had two different MHI systems have problems in the last couple of days - both machines same sort of age but different models. The first one, the pin of the shrader would not return to its rest position, as if the spring was not strong enough. The spring seemed to have good resistance but would not move the pin far enough.
The second one was just a pump down and remove system job, but again the shrader was pouring gas as soon as I took the dust cap off.
I hope its just a couple of cases of bad luck - I have fitted a lot of MHI units over the last few years, hope its not going to be a common problem with them.

Andy

[AbsoluteWDJ]

Has anybody come across problems with dodgy/broken shrader valves on R410a systems? I've had two different MHI systems have problems in the last couple of days - both machines same sort of age but different models. The first one, the pin of the shrader would not return to its rest position, as if the spring was not strong enough. The spring seemed to have good resistance but would not move the pin far enough.
The second one was just a pump down and remove system job, but again the shrader was pouring gas as soon as I took the dust cap off.
I hope its just a couple of cases of bad luck - I have fitted a lot of MHI units over the last few years, hope its not going to be a common problem with them.

Andy

I've had this numerous times. I usually grab the shrader key and untighten, then tighten back. Normally sorts it. I wouldn't put it down to a certain manufacture.

[coolhandlew]

I've had this a lot. Not necessarily on 410 though. Ball valve schrader removal tool a must have bit of kit.

[Andy AC]

I've had this numerous times. I usually grab the shrader key and untighten, then tighten back. Normally sorts it. I wouldn't put it down to a certain manufacture.

That's what I normally do, but when you have r410a coming out at more than standing pressure, its a bit tricky.
I'm gonna have to invest in a r410a core remover then. I have had a brand new R22 core remover in the van for the last 4 years and never had to use it until 2 weeks ago. And now it looks like this may be a regular occurrance, especially with all this leak checking we have got to do.

Andy

[R1976]

I had a Daikin R410A with a dodgy schraeder a few weeks ago.

When I replaced it I then found it had a leak on the coil.:confused:

Took hours to find. Could only hear and see it bubble when GENTLY rocking the coil with all the covers off.:eek:

[jambodaft]

I had a Daikin R410A with a dodgy schraeder a few weeks ago.

When I replaced it I then found it had a leak on the coil.:confused:

Took hours to find. Could only hear and see it bubble when GENTLY rocking the coil with all the covers off.:eek:
I have 3 Daikin R410a RR100 systems, and have problems at least once per year with schraeder valves on the suction ports.
I have just had a system leak with a schraeder that I had just changed 6 months ago!

[R1976]

jambo,

Just thought I'd ask but why do you connect onto the schraeder so much as to find it leaking every year?

Do these systems have history of leaks?

[still learning]

ive, seen this sometimes and wondered if it was caused by, quick release coupllings?

[jambodaft]

jambo,

Just thought I'd ask but why do you connect onto the schraeder so much as to find it leaking every year?

Do these systems have history of leaks?
I have used quick couplings, but it maybe just once per system. I woul'nt put this down as the cause of the faulty schreaders.

[robin r33 gtr]

Are the r410a shrader pins the same as the r22 ones ?

[paul_h]

Yes as far as I know.
I have this happen a lot, especially after liquid charging.
I've learnt never to use a schrader while liquid refrigerant is there, it will freeze the valve up and leak. Always disconnect gauges on the suction after the unit has been running for a while and lkess likely for the valve to freeze up and leak.

The worst thing though is when you come across a schrader that has a narrow entry and you can't fit a tool in there to tighten or replace.

But as many r22 schraders leak for me as r410a if I remove gauges while the system is off or I've just charged liquid, And for the same reason, I don't use liquid line schrader ports unless I really really have too.

[runningonavac]

Had one this morning on a freeezer/r404a. Removed cap, all ok, screwed on my line, checked pressure, went to remove line and found the pin stuck down so tightened line back up and recovered the gas as the compressor was faulty anyway. Have to admit it's not that often a faulty one comes my way, but sometimes it not until you remove your line that you find out. I ALWAYS use quick couplings on 410a systems - alot safer and minimal refrigerant loss.