Topic: CB750K4 brake rebuild service?

[celebutante]

I hope this isn't one of those "use the search bar!" questions, but I can't find anything, so... I've seen guys who do carb rebuilds via mail in the past. Is there anyone up here who does CB750 caliper/reservoir rebuilds if I were to send them? Thanks in advance for any assistance. (I have a '74 CB, BTW)

[bryanj]

Caliper is easy to do yourself as long as you remember to pump the piston out first before undoing any hoses.
Master cylinders can be a real swine and a lot of people opt for the repop sold by Dave Silver as its only marginally dearer than a Honda seal kit and a lot quicker and easier to fit

[newday777]

I hope this isn't one of those "use the search bar!" questions, but I can't find anything, so... I've seen guys who do carb rebuilds via mail in the past. Is there anyone up here who does CB750 caliper/reservoir rebuilds if I were to send them? Thanks in advance for any assistance. (I have a '74 CB, BTW)

Where is "up here"?? I see you haven't posted since 2014. Are you still in Las Vegas?
I haven't seen any offerings of brake rebuild services. Maybe Godffery's Garage (member here) might offer those services???
But as Bryan said, I've read recently of others using the repop masters and calipers with great results. They will definitely be cheaper than finding someone to rebuild yours.
I would highly suggest new brake hoses also to get full power to the caliper as your old rubber hoses will flex a lot by now giving weak brake action, as well as they be deteriorating internally putting junk you don't want into the brake fluid clogging your brake system.

If you are in the states still?? The master cylinder is only $59 from David Silver Spares in PA.

https://www.davidsilverspares.com/CB750K5-FOUR-1975-USA/part_123915/

The new repop caliper is a bit more for $169 but you get all the parts new and don't have to extract your old piston and if your piston might have rusted piston from sitting in damp conditions () then it will need to be replaced.

 brake hoses
Upper
https://www.davidsilverspares.com/CB750K5-FOUR-1975-USA/part_231122/

Lower
https://www.davidsilverspares.com/CB750K5-FOUR-1975-USA/part_189715/

David Silver full offering of K4 parts
https://www.davidsilverspares.com/CB750K4-FOUR-1974-USA/

[celebutante]

Thank you for your thorough reply! To answer you first question, nothing too crazy "up"... indeed I am the same guy! Been ages since I've posted, the answer is a couple of things...

- I got a Ducati Sport Classic 1000 in 2014, so my poor CB was somewhat neglected. But my aging back and wrists really want the option of a not-crazy bike these days.

- I'm (thankfully) no longer in Vegas. Before that, I was in LA for 25 years, which is a FAR more bike-friendly place to live - lots of good places to ride. Vegas is a horrible place for a bike, because it's mostly a grid of traffic lights, surrounded by a big loop of freeways. You have to get pretty far out to find good riding... and of course, there's the weather, which is only really bike-friendly for 6-8 weeks, otherwise too cold or too hot.

But the elephant-in-the-room problem is that Vegas hands-down has the worst drivers of anywhere I've ever lived, so riding a motorcycle there is taking you life into your hands. As a result, I barely rode either of my bikes for roughly a decade - I'd see someone run a red light almost every time I left the house. It was an endless cavalcade of nitwits piling up their vehicles, ambulances, fire trucks, the works.

For many reasons, this year my wife and I relocated to North Stamford, Connecticut. If you're not familiar, it's a fantastic place for riding (other than winter) - endless curvy roads and postcard-beautiful scenery everywhere you look. And said roads begin at my driveway. By a stroke of luck, my next-door neighbor is an ex-racer bike nut with a barn full of bikes, so I have an excellent guide. My currently non-running CB750 is sitting in his barn, so we're wanting to get it back on the road (besides the brakes, carbs are in a box right now, but it's otherwise in good shape).

Bringing me to the front brake issues...moisture definitely not an issue - in Vegas everything dries out, so will be replacing hoses, brake lines, etc. Repop caliper + aftermarket master cylinder sounds good to me, will definitely look into that. My CB is pretty clean and stock, but it's never going to be a concours-circuit queen, so I'm not worried about stock parts (PLENTY of that action out here if you're into the Ferris Bueller/Cameron's dad car thing some bikes, but mostly megabuck cars owned by hedge-fund managers that only see the light of day at Cars and Coffee).

[HondaMan]

My CB is pretty clean and stock, but it's never going to be a concours-circuit queen, so I'm not worried about stock parts (PLENTY of that action out here if you're into the Ferris Bueller/Cameron's dad car thing some bikes, but mostly megabuck cars owned by hedge-fund managers that only see the light of day at Cars and Coffee).

Your bike sounds like mine: it has bruises (no rust) and daily-rider cosmetics, always has.
Some of those megabuck 'Cars and Coffee' show cars there have my custom-built Transistor Ignition inside, hidden somewhere, with switches on them to let the car(s) run on points for the show-winning extra credit that brings. Then they switch back to Electronic mode the rest of the time so the points don't wear out, as they are hard to get these days. There's another bunch down in Virginia (Myrtle Beach area) who have worked with the guys near you, too, with shows and competitions and such. They're the ones that started the "hidden Ignition" thing. It wasn't voted to be 'cheating', but as an 'aid' to help keep the old cars alive.

[bryanj]

Rebuilding calipers is really easy, as long as you pump the piston out FIRST.

All you need is $10 seal and a new piston, preferably stainless, the kit in UK is about £35GBP and it takes about 30 minutes, all you need is a dental pick