Sheridan Model B Sporter

[jirushi]

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

[ratbuster2240]

That's a good challenge to take on, I hope you can getting it shooting again.

[Mark D]

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

[cinedux]

Hi Louis!UJ will supply a repair manual upon request....Trev

[jirushi]

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.

[jirushi]

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.

[--ped--]

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

[jirushi]

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

True that. But I am very ocd in the sense that things must be taken apart!
It's fun!

[jirushi]

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

[Lawrie Amatruda]

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

Louis,

Believe me, do not heat it with a propane torch (no need to), if you feel the urge, use an electric paint stripping gun.

Lawrie.

[jirushi]

Louis,

Believe me, do not heat it with a propane torch (no need to), if you feel the urge, use an electric paint stripping gun.

Lawrie.

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

[ratbuster2240]

Well done Louis. It does look like a solid piece of engineering.

[jirushi]

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

[ratbuster2240]

That's very healthy power for an 80 year old airgun. Will you use a polyurethane material for the inlet seal?

[jirushi]

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.