Topic: 1389 not compressing

[Brimfire]

As a first dip of my toes into the Crosman pool, I'm looking at a 1389.  It comes in near spotless external condition and with the original packaging and manual, not that I get excited about such things as I'm more a shooter than a collector.  The only thing missing is the rear sight blade and I could easily live with that as it would probably only be used with the fitted Nikko Sterling 4x20 or a red dot.



I got my hands on it at the club range last night and, I'm afraid to say, things didn't go well.  Two, 10 pump shots landed on a 17cm, 10m card but then things went south.  It stopped compressing and a hiss from the comp. tube area could be heard.  A couple of drops of PellGun oil did nothing for it.  Testing for the source of leak with tissue paper didn't narrow things down and I don't want to break out the leak detector/soapy water until I'm ready to strip it down.



And there's the problem.  I've got the gun home with me but I'm not sure about buying it until I get a handle on how likely/easy/expensive it'll be to repair.  If it's just a question of a couple of O rings then fine but if it possibly needs a new piston/valve/machining then, as someone (currently) unafflicted with Crosman-itis, I may just bale out.

Can anyone suggest what the fault and cure may be please?

[ped]

not hard to fix as i mentioned on AGF
it's nice if you don't buy it i would have no problem adding it to my colledtion of 1389's lol

[Brimfire]

Hello again Ped.

Just maximising my chances of replies by posting there as well!

I've got first dibs on this but, if I don't go for it, I'll pass your name onto the seller.   

[ped]

cheers

[rangerfredbob]

A whole valve from Crosman used to be like $6, it's either the piston seal, valve outer O ring, check valve or exhaust valve none of which are the end of the world, just take the pump pivot pin out, pull off the whole grip frame and some other stuff that should come right off easy then push the valve out the front. It should be a brass valve in that vintage so a little more sturdy than the current aluminum. There's likely loctite between the two valve halves so heat might be needed and some way to turn the halves without marring them too bad. I think that might have a different check valve than current but I might be confusing things.

If the price is right it should be an easy fix no matter what, it's not like the inside of the pump tube is rusted or anything so it's not completely clapped out...

[Brimfire]

Thanks rangerfredbob.   

I've since found that the sound of the leak alters depending on whether the loader is in or out.  This, to me, means the air is escaping out the transfer port in the breech indicating an exhaust valve fault at the very least.

Ped has offered (on AGF where I also posted this) to provide an exchange service on the valve and I might take him up on that.  My stumbling block is the plastic breech loader though.



It feels flimsy and not built to last.  Or even seal very well for that matter.  If/when it breaks, would I be left looking for unobtainable parts or would some other breech fit straight on?  If another breech (even a stock plastic bolt one) is an easy fallback then I think I'd go for it.  Please bear in mind that this is my first experience of Crosmans and I'm still finding my way with them. 

[Brimfire]

Ped parts on the way!

[Brimfire]

Ped parts (exchange valve, cup washer and TP seal) fitted and it's spitting out pellets.  Great consistency with five shots at 368-369fps on five pumps.  10 pumps gave 469-470 fps.  And that's with a leaking breech which blows air into my face with every shot.

The Wise One says that the barrel can be moved back a fraction to tighten up the breech sealing but that runs the risk of breaking the pop-out loader.  Think I'll heed his words and leave it as is.

I wasn't expecting much accuracy-wise but the first five shots (standing, unsupported) produced a ragged, one hole group.  Admittedly at loft ranges but I was pleased with it.

[ped]

glad you got it sorted Bri