CB400/4 FRONT FORK REFURB BY JULIE

[Nurse Julie]

I suppose it's a lesson to all of us. Never assume that the old parts were fitted correctly in the first place!
Even factory original parts can be fitted wrongly. 

Yep, bloody previous owners, they have a lot to answer for at times !!!
And I thought I was doing so well. Never mind. I wonder if that's why the forks got stuck down sometimes ?

[taysidedragon]

I suppose it's a lesson to all of us. Never assume that the old parts were fitted correctly in the first place!
Even factory original parts can be fitted wrongly. 

Yep, bloody previous owners, they have a lot to answer for at times !!!
And I thought I was doing so well. Never mind. I wonder if that's why the forks got stuck down sometimes ?

It may be. The stantions are straight aren't they? 
Your rebuild is going really well. The fork seals are just a little hiccup. Everybody has them so no big deal.

Looking forward to the rest of the bike rebuild. 

[hairygit]

Just DON'T try re using those seals again, get new ones, a few pounds spent now will save a lot of cursing and swearing later if they leak and you have to strip them a 3rd time!

Sent from my X6pro using Tapatalk

[kevski]

I suppose it's a lesson to all of us. Never assume that the old parts were fitted correctly in the first place!
Even factory original parts can be fitted wrongly. 

Yep, bloody previous owners, they have a lot to answer for at times !!!
And I thought I was doing so well. Never mind. I wonder if that's why the forks got stuck down sometimes ?

The air in the forks was probably being pushed out through the seals, and then a vacuum was created when the forks were going back up slowing the return to normal height and momentarily sticking from time to time, i am surprised you wern't leaking oil, in the right way up the pressure build up in the cavity makes the seal expand against the stanchion creating a tighter seal keeping even the air in, you will certainly notice the difference, better to find out now rather than finding 300ml of oil over your tyres when out riding it, doesn't bear thinking about, the coiled spring sits in a lip and i have not known one to come off yet.
We are nosey buggers, but sometimes it helps.

[matthewmosse]

Minor setback when you are otherwise doing extremely well. It is one of my pet hates in manuals is when they say assemble in reverse order of disassembly. This is no use if someone has been in there before or the part you are trying to fix has come apart in service. About 75% of the stuff I work on is already not functioning or been apart before, so if I am reaching for the manual is nice to check what should be there, and how it should be installed. About the only manual I know that shows this is the old 60s land rover one that gives exploded parts diagrams.

[Nurse Julie]

I suppose it's a lesson to all of us. Never assume that the old parts were fitted correctly in the first place!
Even factory original parts can be fitted wrongly. 

Yep, bloody previous owners, they have a lot to answer for at times !!!
And I thought I was doing so well. Never mind. I wonder if that's why the forks got stuck down sometimes ?

It may be. The stantions are straight aren't they? 
Your rebuild is going really well. The fork seals are just a little hiccup. Everybody has them so no big deal.

Looking forward to the rest of the bike rebuild. 

Yep, stantions are straight

[Nurse Julie]

Just DON'T try re using those seals again, get new ones, a few pounds spent now will save a lot of cursing and swearing later if they leak and you have to strip them a 3rd time!

Sent from my X6pro using Tapatalk

Yes Mr Hairy, I will use new ones.

[Nurse Julie]

I suppose it's a lesson to all of us. Never assume that the old parts were fitted correctly in the first place!
Even factory original parts can be fitted wrongly. 

Yep, bloody previous owners, they have a lot to answer for at times !!!
And I thought I was doing so well. Never mind. I wonder if that's why the forks got stuck down sometimes ?

The air in the forks was probably being pushed out through the seals, and then a vacuum was created when the forks were going back up slowing the return to normal height and momentarily sticking from time to time, i am surprised you wern't leaking oil, in the right way up the pressure build up in the cavity makes the seal expand against the stanchion creating a tighter seal keeping even the air in, you will certainly notice the difference, better to find out now rather than finding 300ml of oil over your tyres when out riding it, doesn't bear thinking about, the coiled spring sits in a lip and i have not known one to come off yet.
We are nosey buggers, but sometimes it helps.

Carry on being nosey Kevski, if it's to my benefit  . Never had an oil leak on these forks, just the sticking down at times

[Nurse Julie]

Well, I was just about to take these forks apart and Trig came in. The exact words were' what the bloody hell are you doing?'
So I explained that I had put the seals in the same way I had taken them out and as a result, they are upside down. 'No they are not' he said. Anyway, I have now had a teaching session on Genuine Honda fork seals, which is what I took out and replaced them with genuine Honda ones.

This picture is showing the upper side of the seal, with the spring and the writing on the seal. The inner lip of the seal is soft and supple and the spring compresses this.

[ Guests cannot view attachments ]

This picture is showing the underside of the seal. The inner lip is very soft and supple. There is also a spring in the rebate which is a lot thicker and stronger than the one on the top.

[ Guests cannot view attachments ]

Trig says fork oil seal is always fitted with any numbers etc facing upwards or outwards.

Therefore I have fitted them correctly and do not need to strip them down again. Phew 

[Clem2112]

Usually find the need to remove old fork seals etc by employing the two woodscrew and pull method..... assisted by added heat from warming the legs with hot water.  So the closed side of these is uppermost....usually has the makers name and part number on this side too !
The stiction could have been from these being assembled  the wrong way up?

Many like to polish the aalyy bits...I gave the fork legs the "original" brushed finish using emery to remove the corrosion and dinks then different grades of scotchbrite to get the finish.... then a coat or three of clear lacquer to protect them.

[Green1]

It would be great to find out what's causing them to stick. I replaced the forks  on the CG with new Chines ones and they occasionally bottom out and stick down you have to pull on the bars whilst riding to bring them back up again.
I'm sure someone at work once told me it can happen with the wrong amount of oil in them.

The fork seals in my Pegaso have springs on both sides I always assumed this was because it has upside down forks.

[kevski]

There we go, learn something new every day, 350f ones were different, i on a personal note would use different ones, just don't like the coil spring on the outside, that is naturally there to help keep the top clamped to the stanchion.

[Nurse Julie]

Here are both the springs side by side.

The one on the left being thicker and a lot stronger is from the underside, the one on the right the upper side one.

[ Guests cannot view attachments ]

[kevski]

Just looked up the seals, and different for both bikes, still first time iv'e seen those seals, so special seals then.

[Nurse Julie]

Just looked up the seals, and different for both bikes, still first time iv'e seen those seals, so special seals then.

Not special as such, just OEM CB400/4