hello All,
Ok........here goes.
I'm pretty sure it's not a Best Fittings or Dr Bob quick fill (unless it's a version I've not seen ?).
The bottle has not relocated at all as far as I can tell.
The blanking plate has gone and been replaced with a brass quick fill, that is now leaking, a lot.
So any pointers would be very welcome.
Thanks Andy
? ? ? if it's leaking from the dowtey washer change it, if it's leaking through the QF itself strip it & look for the problem,
it might be obvious when you look.
A bit of soapy water will help locate the leak...
It could be the dowty that seal wear the QF screws in...
(https://photos.imageevent.com/scl_electronics/gun/air/1_4%20bspp%20qf.jpg)
or an O-ring on the sealing shuttle in the QF..
(https://photos.imageevent.com/scl_electronics/gun/air/websize/foster3.jpg)
Good Luck,
Stuart
Quote from: Ca_Varminter on November 09, 2025, 03:21:48 PMA bit of soapy water will help locate the leak...
It could be the dowty that seal wear the QF screws in...
(https://photos.imageevent.com/scl_electronics/gun/air/1_4%20bspp%20qf.jpg)
or an O-ring on the sealing shuttle in the QF..
(https://photos.imageevent.com/scl_electronics/gun/air/websize/foster3.jpg)
Good Luck,
Stuart
Ah thanks Stuart,
That's a very helpful photo, yes it's ok for the metal washers but leaking (gushing) through the one way quick fill......that makes sense why.
I'll investigate.
Quote from: angrybear on November 09, 2025, 03:05:38 PM? ? ? if it's leaking from the dowtey washer change it, if it's leaking through the QF itself strip it & look for the problem,
it might be obvious when you look.
Thanks
Ok, I removed the quick fill brass part and the metal (crush washer ?) seems a bit mangled now, so I guess another one of those is a good idea (but am sure that's not the original issue that I had).
The "setting" for the one way brass quick fill valve has a tiny o ring that seems ok but I am unsure how to set this screw (and for it to stay set correct) and o ring to hold air.
I seems very loose and looks prone to moving even if I can get an initial seal.
Thanks for humouring me.......i know I don't know what all the bits are called and have no clue what I'm doing !
I may need an expert on the job.
Thanks Andy
Ok....
The Dowty sealing washer has been trashed....It needs to be Replaced..
The QF looks to be a homemade Custom job...
So that screw with an O-ring...
Strange.. Is the screw hollow??
is there any sort of core in the brass piece???
I am assuming there is a shuttle like piece internally!
With type of QF there is no "Valving",, It uses the High Air Pressure(HPA)
to force the shuttle to seal!!!!
So it is only leaking at the Dowty washer seal..Replace it!!
No air leaking from the QF... Don't worry about a this point in Time!
Good Luck,
Stuart
Quote from: Ca_Varminter on November 09, 2025, 05:37:12 PMOk....
The Dowty sealing washer has been trashed....It needs to be Replaced..
The QF looks to be a homemade Custom job...
So that screw with an O-ring...
Strange.. Is the screw hollow??
is there any sort of core in the brass piece???
I am assuming there is a shuttle like piece internally!
With type of QF there is no "Valving",, It uses the High Air Pressure(HPA)
to force the shuttle to seal!!!!
So it is only leaking at the Dowty washer seal..Replace it!!
No air leaking from the QF... Don't worry about a this point in Time!
Good Luck,
Stuart
Thank you Stuart, i really appreciate the help.
Were you able to view the short video I added the the first post ?
In the meantime ill see if i can work out whats inside the brass quick fill.
No hole in the screw, and no obvious way for it to hold in place.
I'm thinking it's going to vibrate loose from shooting or driving, especially if air pressure drops.
I'm wondering if I'd be better to buy the quick fill part per your photo or ask Kev G to sort for me ?
My brass part looks quite extended compared to others I may be able to source / replace with, giving me another headache.
Thanks Andy
OK....
I think I figured the QF out...
I bet the screw is tiny bit loose...
So this will allow the +200Bar air to force it's way pass into the Rapid.
The as the pressure builds, this force the screw and O-ring to seal...
if you want a better QF setup... go to Best Fittings...
1/4"bspp...
https://www.bestfittings.co.uk/shop/fill-probes-adaptors/high-pressure-fill-valves-caps/best-fittings-stainless-steel-high-pressure-fill-valve/
Stuart
Thanks Stuart,
That makes sense, I've just ordered that part. Fingers crossed I'm up and running soon.
Thank you for all your help.
Ok, great!!
You may need to update your Order....
I assume that that old brass QF extended beyond the bottom of the stock.
So the new One from good fitting will be below the bottom of the stock by a bit...
You will need an extended QF socket to reach it!!
Something like this:
(https://photos.imageevent.com/scl_electronics/gun/fxm3/websize/20221021_160152.jpg)
Stuart
Mmmmmmm Carbon !
I'll happily use tweezers, or take it out of the stock for the first go.
I'll be so happy if it's sorted this week, likely make a trip to the Gunshop for some other stuff anyway, so can add one of those, ha ha.
Well that didn't work !
Started off really promising (and I did buy the extended quick fill attachment), good on Best Fittings for including it in the kit.
But the original brass part is significantly smaller than the Best Fittings 1/4" fill valve, and it definitely will not fit.
I'm majorly disappointed, as I'd hoped to be up and running and on the rats this week, but that's not looking likely with the Rapid.
I'm going to sleep on it, for likely a few days but am currently considering this list of options:
• buy a blanking plug (so ditch the quick fill completely) and fill the buddy bottle and just use the rifle.
Is there any reason that would not work ?
• persevere with the brass part (using varying "torque" settings for the inner tiny o ring) and see if the rifle is usable. Not a long term fix and probably would take a back up rifle incase it dumps all of its air.
• Book in with KevG for a real fix
• force fit the best fittings part (this is the least favoured option).
• Dispose of the rifle via a RFD, get a 1-1 variation and get something new......I'll likely forget about this option tomorrow, but it's how I'm thinking right now
• think of something else
Arrrrrrggggghhhhhhh !
I know some or all of this is down to past fettling (before I owned the rifle).
Mighty frustrating.
I am truly sorry for any mis-information I may have passed on.....
Here is a comparison of 1/4" bspp plug from one of my Rapid MKII to a 1/8" bspp fitting....
(https://photos.imageevent.com/scl_electronics/gun/hpafittings/websize/Quarter%20to%20Eighth%20bspp.jpg)
I think I made a mistake assuming your rapid was a MKII...
Is it a MKI??
So someone may have drilled and tapped a 1/8" bspp hole (not normal on MKI) and made the custom QF..
I wish I was on your side of the POND to make this Right!
Sorry,
Stuart
Hey Stuart,
Zero of my predicament is on you.
I appreciate all the help that you have given.
My custom / homemade (not by me) brass quick fill may have other implications.
I'll take some measurements tomorrow to hopefully shed some light on the mismatched parts, it doesn't look to be out by much but enough to be a problem and not want forcing.
I believe it's a 100% Mk 2, but could have been messed with more than I thought.
I'm extra grumpy today as I spent 7 hours in an Apple store (and I don't work there). Not even my phone being messed with.
A solution is getting closer, even if it doesn't always feel it.
Cheers
Andy
Thanks Andy...
Well I looked at you all your photos...
Yes your Rapid is a Early MKII with the Sporter Trigger(teardrop safety knob)
So It should be 1/4" Bspp..
My Head is Spinning on this one.. Since I not there.....
I think we need KevG to check it out!!!
Cheers M8, keep me in the loop on this one!!
Stuart
As I eat my dinner on the this side of the pond...
To measure the size of the hole ..if it is 1/4"bspp...
Check it against your bottle!
The bottle thread is also 1/4" bspp!
Stuart
The Huma foster connection seals the same way with a screw and a oring, why not renew the oring and washer and you are good to go. If it worked in the past and worked well why change it.
it's a mk2 so should be 1/4 bsp thread in the block unless it's been moded for some reason.
kevG
Thank you for your advice everyone, I've made some progress.
Having looked at the threads a little closer, it looks like the new silver quick fill is some 20 thou greater diameter than the old brass one. Measured very roughly with calipers.
So, bearing in mind I'm only at the trainee engineer stage ! No thread gauges to hand, and even if I did have them I wouldn't know what to do with them.
I put the new quick fill in my "brushless Dewalt lathe" (basic drill !) and went at it with the heaviest grit paper I could find !
Turns out I spun it enough to make a difference and although a very tight fit (I also went back and forth gently as if tapping it, with the new quick fill) it seated ok with a new washer and felt reasonable.
I was glad of the extended quick fill, as the 1/4 BSP part is very deep in the stock, with no extra stock nibbling needed.
One thing I did get was extra noises on filling (I went slowly and stopped at 150 BAR). I slightly backed off the screw in the extended quick fill, which didn't seem to make any difference.
I'll be able to check it again in 24-30 hours and chrono it, then fill to 200 BAR and get testing properly.
I don't want to count my chickens too soon, but I'm hopeful and keeping my fingers crossed.
Thanks Andy
It looks like it has worked, 30 hours since the quick fill fitting and 150 BAR fill and first three shots.
I am a happy as Skippy the Kangeroo.
More testing soon, and straight onto the scally tails.
Thank you all for your help.
Andy