Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 23rd April 2017, 11:37   #1
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,262
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default Expansion tank cap 'O' rings

I've been looking at mine today with a view to renewal and have made a surprising discovery. I don't remember this being mentioned on the forum.

The two 'O' ring retaining channels on my original cap (rated '100') are different sizes. Measured with a vernier caliper, the top one is 24.1 mm diameter and the lower is larger at 25.1 mm. So I checked (as best I could) the OD of the two original 'O' rings and, sure enough, there was a difference of 1 mm in the diameters of these too.

So it appears that two new 'O' rings of differing sizes are required. I wonder whether the aftermarket suppliers of these for the 75/ZT have spotted this?

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 23rd April 2017, 12:28   #2
suzublu
This is my second home
 
suzublu's Avatar
 
rover 75 1.8 vvc club se wedgwood blue

Join Date: Aug 2009
Location: Seaton Carew
Posts: 26,880
Thanks: 65
Thanked 7,142 Times in 4,642 Posts
Default

Indeed Simon, Jack who supplies the viton replacements, even sends instructions where to fit each different sized ring
So at least he is aware
suzublu is offline   Reply With Quote
Old 23rd April 2017, 14:33   #3
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,262
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

So not a new discovery on my part then!

Who is Jack please Ronnie?

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 23rd April 2017, 14:38   #4
suzublu
This is my second home
 
suzublu's Avatar
 
rover 75 1.8 vvc club se wedgwood blue

Join Date: Aug 2009
Location: Seaton Carew
Posts: 26,880
Thanks: 65
Thanked 7,142 Times in 4,642 Posts
Default

Quote:
Originally Posted by SD1too View Post
So not a new discovery on my part then!

Who is Jack please Ronnie?

Simon
Jack makes the temp gauge amongst many other parts for our cars. Can be found on EBay. http://www.ebay.co.uk/itm/Rover-75-M...0AAOSweW5VXOLW
suzublu is offline   Reply With Quote
Old 23rd April 2017, 21:40   #5
SD1too
Doesn't do things by halves
 
SD1too's Avatar
 
Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model.

Join Date: Mar 2007
Location: Former Middlesex
Posts: 20,262
Thanks: 1,587
Thanked 3,749 Times in 3,181 Posts
Default

Thank you very much Ron. I can always rely on you for a swift and appropriate reply.

Simon
__________________
"Whatever is rightly done, however humble, is noble."
Sir Henry Royce.
SD1too is offline   Reply With Quote
Old 23rd April 2017, 21:42   #6
trikey
Premium Trader
 
trikey's Avatar
 
Rover 75

Join Date: Nov 2010
Location: Devon
Posts: 33,710
Thanks: 8,837
Thanked 14,831 Times in 8,030 Posts
Default

Quote:
Originally Posted by suzublu View Post
Jack makes the temp gauge amongst many other parts for our cars. Can be found on EBay. http://www.ebay.co.uk/itm/Rover-75-M...0AAOSweW5VXOLW
And having fitted a couple of the temp gauges for members, I can recommend them - A great bit of kit.
__________________
Lest we forget..
trikey is offline   Reply With Quote
Old 24th April 2017, 22:33   #7
Arctic
Give to Learn
 
Arctic's Avatar
 
Freelander 2

Join Date: Aug 2010
Location: West Midlands
Posts: 18,648
Thanks: 1,155
Thanked 6,407 Times in 3,874 Posts
Default

Quote:
Quote:
Originally Posted by SD1too View Post
I've been looking at mine today with a view to renewal and have made a surprising discovery. I don't remember this being mentioned on the forum.

The two 'O' ring retaining channels on my original cap (rated '100') are different sizes. Measured with a vernier caliper, the top one is 24.1 mm diameter and the lower is larger at 25.1 mm. So I checked (as best I could) the OD of the two original 'O' rings and, sure enough, there was a difference of 1 mm in the diameters of these too.

So it appears that two new 'O' rings of differing sizes are required. I wonder whether the aftermarket suppliers of these for the 75/ZT have spotted this?

Simon
Hi Simon.
Drop me your address and name and I will pop some in the post for you, I have been fitting these at nano meets for ( FOC ) since about 2012 I purchased about 150 of each size along with the intercooler rings, after finding out about them in 2011, I am almost sure I did a write up about it back then.

I would think if every member went out and checked the coolant cap 9 times out of 10 the O-rings will be flat and need changing.

They are Viton ones cheers Arctic
Attached Images
File Type: jpg SDC15393.jpg (119.9 KB, 21 views)
File Type: jpg SDC16945.jpg (130.4 KB, 21 views)
File Type: jpg SDC16946.jpg (123.0 KB, 20 views)
File Type: jpg SDC19319.jpg (133.4 KB, 21 views)
__________________
Arctic
Givology Learn to Give
Everything is Achievable

ad altiora tendo.

Check out our Nano meet dates
http://www.midlandsnanomeets.co.uk/

http://www.the75andztclub.co.uk/index.php?thepage=howto

" You do the work , we supply the expertise "

Last edited by Arctic; 12th January 2019 at 11:30..
Arctic is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 09:53.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd