Roundhouse sight glass leaking
- tom_tom_go
- Driver

- Posts: 4824
- Joined: Wed Feb 23, 2011 3:08 am
- Location: Kent, UK
- Contact:
Roundhouse sight glass leaking
Noticed this today, water dribbles from the bottom of the gauge (the metal surround plate is removed to show the leak):
It only leaks when there is pressure in the boiler.
Can I repair it, does it just need descaling?
It only leaks when there is pressure in the boiler.
Can I repair it, does it just need descaling?
- tom_tom_go
- Driver

- Posts: 4824
- Joined: Wed Feb 23, 2011 3:08 am
- Location: Kent, UK
- Contact:
Re: Roundhouse sight glass leaking
Cleaned it last night (the glass panel just pops out) but this morning even with no pressure in the boiler it still leaks.
I have emailed Roundhouse, odd one this.
I have emailed Roundhouse, odd one this.
- tom_tom_go
- Driver

- Posts: 4824
- Joined: Wed Feb 23, 2011 3:08 am
- Location: Kent, UK
- Contact:
Re: Roundhouse sight glass leaking
No seal as far as I can see so I made a gasket from coffee filter paper and seems to have fixed it for now.
I will see what Roundhouse say when they email me back.
I will see what Roundhouse say when they email me back.
- tom_tom_go
- Driver

- Posts: 4824
- Joined: Wed Feb 23, 2011 3:08 am
- Location: Kent, UK
- Contact:
Re: Roundhouse sight glass leaking
No seal as far as I can see so I made a gasket from coffee filter paper and seems to have fixed it for now.
I will see what Roundhouse say when they email me back.
I will see what Roundhouse say when they email me back.
- IanC
- Trainee Driver

- Posts: 798
- Joined: Mon Feb 15, 2016 9:15 am
- Location: Nr. Warrington, Cheshire
Re: Roundhouse sight glass leaking
Interesting to see that no one has offered any advice or a solution. None of my locos have a sight glass so I've not had the problem. My only thought would be to use a smear of silicone sealant. On the full sized locos the gauges often weep a little. However that can sometimes be cured by tightening up by hand, the two securing nuts at the top and bottom of the water tube. It only takes the slightest of adjustment. They are also changed after 21 steamings as a precaution against them breaking in traffic.
Ian
-
Big Jim
Re: Roundhouse sight glass leaking
I am surprised that there is no seal on the gauge. A weep under pressure and then a leak when could would suggest to me a failed gasket .
Not having a loco with a glass like that I can't dismantle one to have a look.
I agree with Ian that a smear of silicone may be belt and braces.
Just out of interest, have you had the glass out or just put the gasket between the two brass mating surfaces?
Not having a loco with a glass like that I can't dismantle one to have a look.
I agree with Ian that a smear of silicone may be belt and braces.
Just out of interest, have you had the glass out or just put the gasket between the two brass mating surfaces?
- tom_tom_go
- Driver

- Posts: 4824
- Joined: Wed Feb 23, 2011 3:08 am
- Location: Kent, UK
- Contact:
Re: Roundhouse sight glass leaking
The gasket I made is wedged between the steel plate and the sight glass.
Mr Roundhouse is sending me a new seal so when I get it I can work out what and where it is located!
Mr Roundhouse is sending me a new seal so when I get it I can work out what and where it is located!
-
gilfachphil
- Fireman

- Posts: 430
- Joined: Sun Nov 24, 2019 11:00 am
- Location: West Wales
Re: Roundhouse sight glass leaking
Now you know!
I am investigating the same issue years later. This is the gasket:-
It is underneath the glass in a machined slot around the edges of the aperture.
I'm waiting on hearing back from Roundhouse about getting hold of a couple.
Phil
I am investigating the same issue years later. This is the gasket:-
It is underneath the glass in a machined slot around the edges of the aperture.
I'm waiting on hearing back from Roundhouse about getting hold of a couple.
Phil
- MRail
- Trainee Fireman

- Posts: 118
- Joined: Mon Oct 26, 2009 4:16 pm
- Location: Merseyside, UK
- Contact:
Re: Roundhouse sight glass leaking
Friend is having a leak problem with a similar gauge on a VoR loco.
Obviously it's a few years old.
He's broken one screw trying to tighten it in hope of stopping the leak.
Coming to me to extract the broken piece and salvage the assembly.
I'm wondering if anyone knows the screw size? I'm guessing 10BA, or perhaps 8BA?
Don't really want to dismantle my own loco to find out!
Thanks,
Rob G (Mrail)
Merseyside
Obviously it's a few years old.
He's broken one screw trying to tighten it in hope of stopping the leak.
Coming to me to extract the broken piece and salvage the assembly.
I'm wondering if anyone knows the screw size? I'm guessing 10BA, or perhaps 8BA?
Don't really want to dismantle my own loco to find out!
Thanks,
Rob G (Mrail)
Merseyside
Rob G
Madog & Mersey Railway (SM32)
In my Father's roundhouse are many loco sheds.
Madog & Mersey Railway (SM32)
In my Father's roundhouse are many loco sheds.
-
Preseli Chris
- Trainee Fireman

- Posts: 249
- Joined: Fri May 24, 2024 4:25 pm
- Location: Land of the Draig
Re: Roundhouse sight glass leaking
Contact Roundhouse. They would know and be able to supply a replacement. They do provide a good backup service.
Yr Tren Nesa Wedi Mynd
- MRail
- Trainee Fireman

- Posts: 118
- Joined: Mon Oct 26, 2009 4:16 pm
- Location: Merseyside, UK
- Contact:
Re: Roundhouse sight glass leaking
Thanks, but been there, done that.
No definitive info, but did send a selection of screws.
He's trying to reassemble with broken screw.
I await report.
No definitive info, but did send a selection of screws.
He's trying to reassemble with broken screw.
I await report.
Rob G
Madog & Mersey Railway (SM32)
In my Father's roundhouse are many loco sheds.
Madog & Mersey Railway (SM32)
In my Father's roundhouse are many loco sheds.
-
gilfachphil
- Fireman

- Posts: 430
- Joined: Sun Nov 24, 2019 11:00 am
- Location: West Wales
Re: Roundhouse sight glass leaking
I second that.Preseli Chris wrote: ↑Wed Oct 29, 2025 11:36 pm Contact Roundhouse. They would know and be able to supply a replacement. They do provide a good backup service.
Having emailed Roundhouse and not received a reply I eventually got round to phoning them. Spoke to a very helpful guy who told me that the water gauge had used three different sizes of O rings over the years and offered to post me one of each for my Silver Lady.
Don’t be shy, give them a call, it works,
Phil
Who is online
Users browsing this forum: No registered users and 2 guests