help sourcing thumb screws for water pump plate

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shoc

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I'm looking to replace the six standard screws on my Jabsco water pump (10970-21) with thumb screws and because I'm not familiar with threads 'n bolts etc I'm having trouble finding suitable replacements.

BTW, access to the water pump is reasonably easy so I don't need the expense of the speedseal option.

To get the spec I've googled the original replacement screws and they are;
Length:3/8" Long
Diameter 8-32 UNC Thread

I cant locate suitable replacements on ebay or amazon and most other google searchers have me bewildered.

Any help-advice?
 
Speedseal screws (for a Volvo D1-30) are M4 and 12mm long, although presumably if they make a cover for the OP's pump the screws will be the correct size.
 
I'll definitely try speedseal for the screws, I hadn't spotted that on the website.

Am i searching for the proper items, I'd been googlying stainless steel thumbscrew unc thread or brass thumbscrew unc thread ?
 
shoc said:
I'll definitely try speedseal for the screws, I hadn't spotted that on the website.

Am i searching for the proper items, I'd been googlying stainless steel thumbscrew unc thread or brass thumbscrew unc thread ?
Click to expand...

You've got your answer from MoodySabre above. You need to include the 8-32 or the search will offer you loads of metric. The small UNC sizes were never common in the UK, we tended to use BA sizes below 1/4".

Edit - cross post, you did look for 8-32, err - no you didn't Moody Sabre did!
 
Last edited:
Quick question guys,
I was going to wait till I'd been to the boat to check the size before ordering thumbscrews for mine. But from the previous posts it sounds like the correct thread for a Johnson pump (mine is fitted to a Yanmar 3ym20) is a 4mm metric thread.
Can anyone confirm this for me and I'll get them ordered sooner.
 
greeny said:
Quick question guys,
I was going to wait till I'd been to the boat to check the size before ordering thumbscrews for mine. But from the previous posts it sounds like the correct thread for a Johnson pump (mine is fitted to a Yanmar 3ym20) is a 4mm metric thread.
Can anyone confirm this for me and I'll get them ordered sooner.
Click to expand...

If you tell Speedseal which engine/pump you have, they'll know which screws you need.
 
greeny said:
Quick question guys,
I was going to wait till I'd been to the boat to check the size before ordering thumbscrews for mine. But from the previous posts it sounds like the correct thread for a Johnson pump (mine is fitted to a Yanmar 3ym20) is a 4mm metric thread.
Can anyone confirm this for me and I'll get them ordered sooner.
Click to expand...
My Johnson are also M4 thread - bought off ebay. Look for stainless knurled thumb screws
 
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