Honda-SOHC

SOHC.co.uk Forums => CB350/400 => Topic started by: Trigger on April 19, 2017, 07:51:36 PM

Title: Oil pump O rings
Post by: Trigger on April 19, 2017, 07:51:36 PM: Does anyone know the thickness of the O ring that is located behind the plate with the 4 bolts on the oil pump. It is about 27mm, but I can not work out the thickness of the old, flat, brittle one.
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 08:05:50 PM: I just measured one that's gone oval; 1.45 x 2.32, so it's probably 2mm
Title: Re: Oil pump O rings
Post by: Trigger on April 19, 2017, 08:08:10 PM: Quote from: mike the bike on April 19, 2017, 08:05:50 PM
I just measured one that's gone oval; 1.45 x 2.32, so it's probably 2mm

Are you getting 27mm ID Mike ?
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 08:19:40 PM: Looks about that. Don't make me get off my arse for the caliper.
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 08:27:15 PM: Get off your arse, I need accurate measurements :-* :-* :-* :-*
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 08:31:40 PM: Wait till I finish this game of crib
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 08:39:50 PM: Crib.........are you joking?
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 08:53:52 PM: No. It's a game for grown ups so go back to your game of snap.

I measured the O ring best I can and it's 30mm
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 08:55:26 PM: ID ?
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 09:11:21 PM: That was the OD. ID is obviously OD - 2t
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 09:17:52 PM: Ok Mike, thanks for that, I owe you anoooooother pint. Trying to stop Hettie leaking like the Torre Canyon. She reminds me of most of my old Triumph's and BSA's at the moment :'( :'( :'(
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 09:20:31 PM: What's up with the O ring, Gone all hard and cracked up has it?
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 09:22:30 PM: Yep, they all had, so having a complete rebuild
Title: Re: Oil pump O rings
Post by: mike the bike on April 19, 2017, 09:34:50 PM: Annoyingly, the gasket set doesn't include that 30mm O ring, the big 60mm (ish) oil pump O ring or the oil filter O ring.
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 19, 2017, 09:43:49 PM: Yes, luckily I found all of the other 7 O rings I needed to overhaul the pump at home, it was just that one I couldn't quite work the size out.
Title: Re: Oil pump O rings
Post by: Bryanj on April 20, 2017, 05:32:09 AM: That sounds like the same size as the 500/550 one
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 20, 2017, 10:27:32 PM: Oil leak all sorted........at last. 18 month ago I noticed a few drops of oil on the floor which had been running down the side stand. I looked everywhere for where the leak was coming from and came to the conclusion it was the sump gasket so I changed it but still had a leak. Last summer the leak got worse, investigated again and firstly changed the gear change lever seal, still leaked, so changed the starter motor O ring.......still an oil leak, so changed the sump gasket again as there was always oil along the line of the sump....still leaked, but alot worse now. Only thing left on that side at that level was the oil pump. Took it apart and every O ring was hard, brittle and squashed flat. All new O rings fitted......bingo, dry as a bone at last.
Title: Re: Oil pump O rings
Post by: Trigger on April 20, 2017, 10:30:51 PM: WAIT until you refill with oil .
Title: Re: Oil pump O rings
Post by: hairygit on April 20, 2017, 10:32:15 PM: Quote from: Trigger on April 20, 2017, 10:30:51 PM
WAIT until you refill with oil .
I can see someone getting laxatives in their next meal..........

Sent from my X6pro using Tapatalk
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 20, 2017, 10:34:56 PM: Err, you mean the meal he has just eaten ;D ;D ;D ;D
Title: Re: Oil pump O rings
Post by: Dave487 on April 24, 2017, 09:15:41 PM: I recently ordered the following from Mayday Seals after a bit of investigation from this forum and some guestimates

7 mm x 1.5 mm O-Ring - Material : Nitrile 70 3 off
16 mm x 2.5 mm O-Ring - Material : Nitrile 70 2 off
27 mm x 2 mm O-Ring - Material : Nitrile 70 1 off
41 mm x 2 mm O-Ring - Material : Nitrile 70 1 off
63 mm x 2.5 mm O-Ring - Material : Nitrile 70 1 off

They all seem to fit ok when I re-assembled the pump but I haven't run the engine yet so not checked the pressure or for leaks.
Title: Re: Oil pump O rings
Post by: Nurse Julie on April 24, 2017, 10:01:35 PM: Agree with the 7mm x 1.5mm, 63mm x 2.5mm and 27mm x 2mm.........but I put different size O rings in to the others you mention. All viton. Mine is up and running, with good pressure and no leaks.