Bowman heat exchanger filler neck replacement

Z

zambant

Well-Known Member
Joined
25 Jan 2010
Messages
430
Visit site
I need to replace the Bowman heat exchanger filler neck on my Thornycroft T80 engine.

I can get a replacement from ASAP Supplies
http://www.asap-supplies.com/marine/heat-exchanger-spares-and-accessories/bowman-filler-neck-3921-1

so no problems there.

BUT they have clearly used brass filler necked screwed into the ali body of heat exchanger.

Has anyone done this job please? It looks like it could be a nightmare due to the corrosion / previous sealant.

What should I use to re seal the new neck please?

Thanks

John
 
omega2 said:
Looks like your going to have to unscrew your one, or clean the area and use plastic metal to reseal.
Click to expand...
Yep -its the unscrewing and re- sealing that I need the advice with :-)
Its not leaking - but the top seal is not effective as the top lip is bent and distorted.
J
 
I have replaced one also, as I recall the inside neck of the filler is a Hex and I had to make a very large Allan key from a short section of Hex bar with length of 25mm box section welded to the top, the bar was approx 18inch long and it was necessary, heat was also applied and was done in situ I refitted the new one with same tool and some loctite 577 on the thread. It was successful.
Philip
 
agent leman said:
I did the same job on the Bowman heat exchanger on my Thornycroft T90 a couple of months ago. I cut the knackered brass filler neck out, cleaned up the alloy and had a replacement alloy filler neck welded on. You need to find a neck that has plenty of metal thickness to it - the neck I used is this one: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=290718735407&ssPageName=ADME:L:OC:GB:3160 . Dave
Click to expand...

I am hoping to screw the old one out and the new one in. Thx for the link - sure will be keeping that one in case I cant get the old one out :-)
How long did it take you to remove the heat exchanger please?
J
 
The heat exchanger was a straightforward job to remove - about 20 minutes or so. I did try to remove the old filler neck but even with heat it stubbornly refused to budge. When I eventually got it out the alloy was in a pretty poor state and needed grinding back several mm's before clean metal was available for welding. Even if I could have removed the old brass filler non surgically I would not have been confident that a good seal could ever be remade. I suggest that you dismantle yours before ordering a replacement brass neck just in case it turns out to be too corroded and a welded one is the only option. Dave
 
agent leman said:
The heat exchanger was a straightforward job to remove - about 20 minutes or so. I did try to remove the old filler neck but even with heat it stubbornly refused to budge. When I eventually got it out the alloy was in a pretty poor state and needed grinding back several mm's before clean metal was available for welding. Even if I could have removed the old brass filler non surgically I would not have been confident that a good seal could ever be remade. I suggest that you dismantle yours before ordering a replacement brass neck just in case it turns out to be too corroded and a welded one is the only option. Dave
Click to expand...
Thanks Dave - good advice.
Regards
John
 
I changed one a couple of weeks ago- resorted to a small cold chisel in the end to cut a vertical slot,then fold the brass in on itself.
The replacement was threaded 1 1/4" BSP so filed out the original hole as required, and retapped the thread.
Sealed with a Loctite liquid thread sealant. All done in position, but easy access to the top of the engine from above.
 
You must log in or register to reply here.

Share this page

Top