« previous next »
Pages: [1]   Go Down

Author Topic: 1978 CB750F  (Read 3525 times)

0 Members and 1 Guest are viewing this topic.

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
1978 CB750F
« on: March 22, 2016, 05:09:53 PM »
So the master cylinder for the rear is soaking its a blob of rust  I really dont know if I'm going to get it apart or even its going to be rebuildable  In case its not is there  a replacement that i can use in  place of the original rear Master I  have an eye on one from a GL1000 it has the built in reservoir  not the separate  cup and hose
Any help would be greatly appreciated
Thanks Tim
Logged

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,832
  • Northern Virginia
Re: 1978 CB750F
« Reply #1 on: March 23, 2016, 07:08:54 AM »
I retrofitted Honda MC for my rear wheel, it was from 944RR I think, used on many Hondas, looks like this:



$20 shipped from ebay.


Edit:  2003 Honda CBR954r thats where the MC is from.
« Last Edit: March 23, 2016, 07:10:40 AM by 70CB750 »
Logged
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #2 on: March 23, 2016, 08:36:58 AM »
I've seen a few like that on there but didn't think it would fit I ordered one for 78 GL1000 looks like the same bolt on pattern as the 750f
I think ...


Sent from my iPhone using Tapatalk
Logged

Offline mick750F

  • Expert
  • ****
  • Posts: 1,395
Re: 1978 CB750F
« Reply #3 on: March 23, 2016, 10:14:50 PM »
 
   David Silver Spares has an OEM rebuild kit for the rear master cylinder for the '78 750F. Years ago, before the interwebnet, I paid handsomely for a NOS rear master cylinder because my at the time "Honda guy" told me it was my only option. It probably was then...

   Usually with a good soak and maybe a little heat you can get them apart. Once apart you can tell whether the body of the MC is good and is usable with new parts. Otherwise you can try to find a usable MC off of a donor bike or go with suggestions for a newer MC.

Cheers
Logged
'
Glosta, MA
It's not the heat...it's the humanity.

Offline martin99

  • UK Based, Non-
  • Master
  • *****
  • Posts: 1,733
  • Adventure before Dementia
Re: 1978 CB750F
« Reply #4 on: March 24, 2016, 11:19:11 AM »
If the GL one doesn't work, the CB750F1 master cylinder (without remote reservoir) has the same bolt pattern and will fit the F2/3. The part numbers for the two (F1 and GL) are different, makes me wonder if there are differences in the internals or length of the actuating rod? The F1 item is direct bolt-on.
Logged
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #5 on: March 24, 2016, 11:37:37 AM »
Quote from: martin99 on March 24, 2016, 11:19:11 AM
If the GL one doesn't work, the CB750F1 master cylinder (without remote reservoir) has the same bolt pattern and will fit the F2/3. The part numbers for the two (F1 and GL) are different, makes me wonder if there are differences in the internals or length of the actuating rod? The F1 item is direct bolt-on.

The F/F1 is different than the GL. The GL has a fitting inside the hose threads and the F/F1 has a hose 'stop' on the outside.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline martin99

  • UK Based, Non-
  • Master
  • *****
  • Posts: 1,733
  • Adventure before Dementia
Re: 1978 CB750F
« Reply #6 on: March 24, 2016, 12:32:20 PM »
Best photo I can find of my old F2 with F1 cylinder fitted. As I said, direct bolt on, no modding necessary

Logged
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #7 on: March 24, 2016, 12:34:55 PM »
That's the problem I can't find any ones f1 to f3
I think the one I have it's not going to work I'm open to any and all suggestions
I see a lot on eBay I just need the master I could use the hose and cup from the one I have now


Sent from my iPhone using Tapatalk
Logged

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #8 on: March 24, 2016, 12:39:10 PM »
Logged

Offline martin99

  • UK Based, Non-
  • Master
  • *****
  • Posts: 1,733
  • Adventure before Dementia
Re: 1978 CB750F
« Reply #9 on: March 24, 2016, 12:46:35 PM »
Logged
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #10 on: March 24, 2016, 12:49:24 PM »
Quote from: Timindecaturga on March 24, 2016, 12:39:10 PM
http://m.ebay.ie/itm/Honda-CB750-CB-750-F1-SOHC-1975-Rear-Back-Brake-Master-Cylinder-/311454356835?nav=SEARCH


Sent from my iPhone using Tapatalk

Thanks for posting that picture! That is a GL master. See how the line goes directly in vs using a banjo bolt? It has an internal fitting that the line mates with. The F master uses a banjo bolt and thus exits at 90 degrees. Where the line attaches to the banjo it has 2 'tits' that hold it in place.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #11 on: March 24, 2016, 12:52:39 PM »
Quote from: martin99 on March 24, 2016, 12:46:35 PM
This one's in the US - pricey though.

http://www.ebay.co.uk/itm/1975-75-HONDA-CB750-F-CB750-CB-750-REAR-BACK-BRAKE-MASTER-CYLINDER-cyl-/321885218187?hash=item4af1daa58b:g:DGoAAOSwNgxWErMV

That is pricey and could be crap. The rebuild kits have been tough to locate but a 75-79 GL works fine. The rod is just a slight bit longer. Someone is now offering an aftermarket kit. SiriusConINC.com maybe? Saw it recently.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline martin99

  • UK Based, Non-
  • Master
  • *****
  • Posts: 1,733
  • Adventure before Dementia
Re: 1978 CB750F
« Reply #12 on: March 24, 2016, 12:56:00 PM »
Quote from: Jerry Rxman Griffin aka MuthaF'er on March 24, 2016, 12:49:24 PM
Quote from: Timindecaturga on March 24, 2016, 12:39:10 PM
http://m.ebay.ie/itm/Honda-CB750-CB-750-F1-SOHC-1975-Rear-Back-Brake-Master-Cylinder-/311454356835?nav=SEARCH


Sent from my iPhone using Tapatalk

Thanks for posting that picture! That is a GL master. See how the line goes directly in vs using a banjo bolt? It has an internal fitting that the line mates with. The F master uses a banjo bolt and thus exits at 90 degrees. Where the line attaches to the banjo it has 2 'tits' that hold it in place.

Yes you're right on that one Jerry, the vendor has described it incorrectly. It also has a plastic bowl, whereas the F1 item has a solid bowl.
Logged
Build threads:
77 750F2 Refresh Project http://forums.sohc4.net/index.php?topic=144075.0
TRIBSA http://forums.sohc4.net/index.php/topic,160296.0.html

1977 CB750 F2
1958 Norton Model 99
2011 Triumph Street Triple 675

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #13 on: March 24, 2016, 01:03:29 PM »
Check this #$%* out! If this works (measure the hole distance) how would it get any better or cheaper??!!

http://www.ebay.com/itm/FOOT-REAR-BRAKE-MASTER-CYLINDER-WITH-FLUID-RESERVOIR-FOR-SUZUKI-GSXR-600-750-/291660514527?fits=Year%3A1975%7CModel%3ACB750F&hash=item43e85244df:g:xaAAAOSwuYVWmL0X&vxp=mtr

Says in the title it fits a 75 CB750F!
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #14 on: March 24, 2016, 01:10:39 PM »
Yea I saw this and thought it would work too I mean I could use the original hose and cup an adjust the linkage to the pedal no?


Sent from my iPhone using Tapatalk
Logged

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #15 on: March 24, 2016, 01:23:46 PM »
The early 75's came out with a nylon bowl. Up to serial 7000 and change then switched to all aluminum for the end of 75 and all of 76. I tried using a NOS GL master first and attempted to remove the fitting inside the threads but snapped my (not) easy out. After that fiasco I removed the guts and the nylon bowl and put them into my original master.
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,832
  • Northern Virginia
Re: 1978 CB750F
« Reply #16 on: March 25, 2016, 02:38:53 AM »
That looks like the one I used, M8 and all that.

Quote from: Jerry Rxman Griffin aka MuthaF'er on March 24, 2016, 01:03:29 PM
Check this #$%* out! If this works (measure the hole distance) how would it get any better or cheaper??!!

http://www.ebay.com/itm/FOOT-REAR-BRAKE-MASTER-CYLINDER-WITH-FLUID-RESERVOIR-FOR-SUZUKI-GSXR-600-750-/291660514527?fits=Year%3A1975%7CModel%3ACB750F&hash=item43e85244df:g:xaAAAOSwuYVWmL0X&vxp=mtr

Says in the title it fits a 75 CB750F!
Logged
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #17 on: March 25, 2016, 12:52:33 PM »
Got the part and it looks like it's going to work
I think. So far I don't see a problem


Sent from my iPhone using Tapatalk
Logged

Offline Jerry Rxman Griffin aka MuthaF'er

  • This MuthaF'er is getting to be a
  • Really Old Timer ...
  • *******
  • Posts: 14,930
  • Bought her new 4/75
Re: 1978 CB750F
« Reply #18 on: March 25, 2016, 05:03:42 PM »
Nice score on an unobtainium part! NOS too. $$? GL or F?
Logged
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Timindecaturga

  • Full Member
  • *
  • Posts: 94
Re: 1978 CB750F
« Reply #19 on: March 25, 2016, 08:20:36 PM »
GL1000 I think it's going to be fine


Sent from my iPhone using Tapatalk
Logged
Pages: [1]   Go Up
« previous next »