Page 5 of 5

Posted: Tue Jan 22, 2008 12:58 pm
by OSCARMARK
The alignment seems fine, my problem is now that I cannot figure out how the master cylinder goes back together.
I have used a genuine Honda rebuild kit with spring piston push rod etc.. The Honda manual shows that the circlip is inserted, then the pushrod. The diagram is clear........... however it seems to make sense that the circlip retains the disc on the pushrod into the body of the master cylinder?? or am I missing something.

Spring inserted
then the small cupped rubber washer
then the piston, the next thing shown in the diagram is the circlip, then the pushrod????

Thanks
Mark

Posted: Tue Jan 22, 2008 1:07 pm
by alimey4u2
The exploded diagram is shown incorrect. If you look at the picture before (showing the dextrous use of the snap ring pliers,) you will see that the circlip retains the pushrod.... :thumupp:

Posted: Tue Jan 22, 2008 1:10 pm
by EMS
This is incorrect?

2283

Posted: Tue Jan 22, 2008 1:12 pm
by alimey4u2
In reality Mike the circlip "should" be shown between "4" & "10"....

Posted: Tue Jan 22, 2008 1:16 pm
by EMS
O.K.! It has been some time since I had one apart. I thought the rod was loose and only held by the rubber boot. The clip prevented the piston from coming out.

Posted: Tue Jan 22, 2008 1:22 pm
by alimey4u2
If you look at page 15-15 in the 79-80 manual, the middle photo shows the circlip in the correct position. It retains the total assy....

Been a while since I have been in there too.... :wink:

Posted: Tue Jan 22, 2008 1:32 pm
by alimey4u2
Page 15-16 bottom left

Rear Master Cylinder Assembly

Install primary cup & piston.
Install pushrod & circlip.
Install the boot, nut & rod eye.

Posted: Wed Jan 23, 2008 12:18 pm
by OSCARMARK
Okay............ the whole thing is back together with all new internals.... as soon as I introduce fluid under gravity via the feed ( 3 ) fluid leaks out of the bottom of the cylinder passed the push rod :cry:

I have stripped and cleaned it again... this time I introduced some fluid via a syringe into the feed,,,,,,,,,,, again fluid leaks out of the base passed the push rod.

There are 2 holes in the feed cavity, a large one and a small one... both are clear. I have read somewhere that these are 'transfer ports'??

Once again guys... I throw myself at the mercy of the experts :oops:

Cheers

Mark

Posted: Wed Jan 23, 2008 12:37 pm
by alimey4u2
Mark, OK the obvious (forgive me) make sure the open end of the cup it up & the correct size, it should be a slight squeeze fit. Make sure the primary cup & backup cup are not rolled. Check the master cyclinder is not scored/grooved/ oversized. Assemble the parts wetted with brake fluid & all should be well....

Posted: Thu Jan 24, 2008 10:09 am
by OSCARMARK
Thanks Larry,

I spoke with John Froude ( UK member ) who works at Hartgate Honda in Mitcham Surrey...... It seems that I have left out a seal :oops:

It seems that there is another in addition to the 'cup' seal that sits on the narrow end of the spring......

The diagram in the manual is unclear ( as it is about the positioning of the circlip ) I have to search my bench for the thing.... I don't even know what it's supposed to look like. presumably its sits on the shaft of the pushrod?

Almost there!!!!

Mark

Posted: Thu Jan 24, 2008 11:33 am
by alimey4u2
That would be the primary cup Mark, you definitely need that.. Looks like a little black rubber cup, like Tommy Coopers Fez without the tassle.... :lol:

Posted: Thu Jan 24, 2008 12:48 pm
by OSCARMARK
Found it!!!!! It looks like the one that fits on the spring but has a hole through it. It is a nice tight fit on the pushrod. All fitted..... brake bled and no leaks!!!!!!!!!!!!!!! :D :D :D

The road was dry this evening so took her out for a couple of miles. Brake does feel strange, but the pads are obviously new.

I am deeply in the debt of the ICOA members who have advised me, specifically Larry.

Thanks again guys and I hope it will be a while before I have to post my next problem!!!

Cheers

Mark

Posted: Thu Jan 24, 2008 2:00 pm
by alimey4u2
Gnus Mark, Hope to meet you at a rally, until then ride safe..... 8)