That's a good challenge to take on, I hope you can getting it shooting again.
Hi,
A friend bought this Sheridan Model B Sporter recently from the USA.
I am going to try to make it work again.
The pump cup doesn't seal in the tube. A friend advised to soak in transmission fluid stop leak.
Hopefully that will work.
I would like to "get into" the valve.
Mostly out of curiosity, but probably because it needs new seals.
There's no info on the net on how to do this.
I guess a special tool is needed to unscrew the valve nut?
Here are a few photos. The gun has seen some life, and I think the barrel blocks have been re-soldered. That might be the reasons why all the paint (B's were painted, A's were chemically blackened) is gone.
Cheers, Louis
That's a good challenge to take on, I hope you can getting it shooting again.
Nice Sheridan to have Louis - makes me jealous that you can import from the US freely.
You know who to ask if you want the definitive answer on the valve
Hi Louis!UJ will supply a repair manual upon request....Trev
Thank you gents.
I shall indeed contact The King of Seals
@Trevor, good tip, I've sent UJ an email.
The pump cup is soaking in "transmission fluid stop leak". If that doesn't help, then I will try to flare it up.
Although I can't unscrew it. It might be Loctited.
The valve is out, with thanks to advice from UJ Backus.
I would like to unscrew it, but it's super duper tight.
The logical thing would be to replace the o-ring and then test if it seals, but it would be interesting to "get inside".
Perhaps it needs some heat, and collets.
sometimes the adage if it ain't broke don't try to fix it springs to mind
but it doesn't look a difficult part to make
I asked UJ about disassembling the valve, and he confirms that they sometimes need a lot of heat, and a lot of force.
The factory used a tough thread sealing compound.
I will have to leave this one closed until I know if it works.
Otherwise I will get the propane torch out
Thank you Lawrie.
The valve is really super tight. I am using collets, but there is zero movement, even if I use all the force I have (admittedly, not a huge amount, but still).
I have decided to leave it. It would be good to at least clean, or better: resurface or replace, the two seals inside. As the inlet valve seems to leak (air pressure is felt on opening the pump arm, from 5 pumps onwards).
The pump cup seals well, after a few "sessions" in the spring compressor.
I am now getting 620 ft/s with 13.73 gr JSB, at 8 pumps. It could be a bit better (my A does 13 ft/lbs on 8 pumps), but it ain't bad.
I will call this project finished for the time being. It will make its way to the owner, my friend in the North of Holland (which in our country means a two hour drive; we think that's very far )
This quad seal off a TR Robb custom Innova pump head (which was rubbish tbh) fits, hooray!
Nice barrel
This was a special moment, when the valve re-entered the gun
I like looking at the gun from every angle
Well done Louis. It does look like a solid piece of engineering.
Cheers ratbuster2240.
It needs more work, both mechanically as comsetically, but I'll leave that to the owner.
I have put the gun "on the rails", it shoots now, that's nice.
I shot my A during the weekend.
On Saturday evening it performed well; a 2 cm group at 30 meters.
At 8 pumps (I thought 13 ft/lbs, but it's 14; 680 ft/s).
But on Sunday, the pellets hit low, and there was less of a BANG.
Tested, power low.
Listened at the valve after pumping; a leak from the inlet.
I guess I'll have to take it apart and kindly ask Lawrie to make new seals
Cheers
That's very healthy power for an 80 year old airgun. Will you use a polyurethane material for the inlet seal?
Yes it packs a punch and it's very accurate too. The sights are great, better than on the B actually (finer foresight).
I think that Lawrie uses polyurethane yes. Hope I will get this A valve apart! It was resealed in 2010 in the USA.
Cheers, Louis
Ps. I know it's sinful but I think I prefer this cheap Crosman 187, shooting wise. 40 shots per powerlet at 620 ft/s, and very accurate. Wish it had grooves for a scope.