Converting right hand front brakes to right hand rear

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apctjb
Posts: 59
Joined: Mon Oct 30, 2017 11:27 pm

by apctjb

Working on my first WW MTB build and in the process of buying components.

Considering getting a complete Shimano XT M8000 groupset but running into difficulty finding group sets that have left hand front, right hand rear currently in stock. There appears to be plenty of stock for the left hand rear, right hand front.

This may be a really dumb question but can't a right hand front be converted to right hand rear by simply swapping the hydraulic lines so that the right hand lever connects to the rear brake? Or is there more two it than that?

mattr
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Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

With care and the right tools you can do it in ~2 minutes and no bleeding needed.

If you bodge it, or are hamfisted, prepare to need to bleed the brakes.

I've done it dozens of times, buying brakes from germany to use on UK set up bikes. Only had to bleed one so far (and i think it would have needed bleeding anyway, it was spongy before i started!)

simoncx
Posts: 99
Joined: Sun Nov 15, 2009 12:27 am

by simoncx

It's a easy swap just change the lines to the lever you need, but you will need a new barb, olive and bleed kit.

mattr
Posts: 3507
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

simoncx wrote:
Sat Jan 27, 2018 3:25 pm
but you will need a new barb, olive and bleed kit.
Only if you are hamfisted, 95% of the time, you won't need them.

apctjb
Posts: 59
Joined: Mon Oct 30, 2017 11:27 pm

by apctjb

Thanks for the responses!

A follow on question. To route the lines (internal routing) I am going to have to disconnect the lines regardless of left front or rear. Do you typically disconnect the line at the brake or the lever, and any tips on how to avoid having to bleed the lines?

mattr
Posts: 3507
Joined: Fri May 25, 2007 6:43 pm
Location: The Grim North.

by mattr

Ow. If it's internal, you'll need all the parts and almost certainly a bleed afterwards.
Think you'll have to disconnect at the lever end, most/all Shimano have one end permanently crimped on, the caliper end. So it won't often fit through internal routing ports.

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MMMhills
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by MMMhills

A trick we do at the shop.

Disclaimer you need to be careful.

With no bleed blocks or rotars between pads gently squeeze the brakes 1-2 maybe 3 times. You will see the pistons come out some. Here is where you need to be CAREFUL do not blow the pistons out of the caliper and make sure both sides come out. sometimes on cheaper brakes only one side will move increasing the risk of unseating the piston.

Then remove/cut the lines at the handle and run the lines. be quick and try to keep open end up so very little fluid drips out. keep both open ends UP so fluid does not keep dripping. If line is cut ALWAYS use a new olive. Then reattach the lines to brake handles and use a brake spreader or screwdriver to puch pistons back in caliper. This pushes any air back in to resivoir. I have done it 100's of times and it works 99% of the time. Sometimes depending on the system you need to add a tiny bit of fluid afterwards but most thew time its good to go.
If you think you can handle 10,000 feet then check out this ride...[/size][size=150]http://www.michiganmountainmayhem.com

apctjb
Posts: 59
Joined: Mon Oct 30, 2017 11:27 pm

by apctjb

With no bleed blocks or rotars between pads gently squeeze the brakes 1-2 maybe 3 times. You will see the pistons come out some. Here is where you need to be CAREFUL do not blow the pistons out of the caliper and make sure both sides come out. sometimes on cheaper brakes only one side will move increasing the risk of unseating the piston.

Then remove/cut the lines at the handle and run the lines. be quick and try to keep open end up so very little fluid drips out. keep both open ends UP so fluid does not keep dripping. If line is cut ALWAYS use a new olive. Then reattach the lines to brake handles and use a brake spreader or screwdriver to puch pistons back in caliper. This pushes any air back in to reservoir. I have done it 100's of times and it works 99% of the time. Sometimes depending on the system you need to add a tiny bit of fluid afterwards but most thew time its good to go.
Thanks for response. Curious to understand; Does this shift some fluid to the caliper so when the hose is cut there is less to leak out or that pushing the calipers back in afterwards forces the trapped air into the levers where it can escape by opening the fill screw?

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MMMhills
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by MMMhills

apctjb wrote:
Mon Jan 29, 2018 4:24 pm
With no bleed blocks or rotars between pads gently squeeze the brakes 1-2 maybe 3 times. You will see the pistons come out some. Here is where you need to be CAREFUL do not blow the pistons out of the caliper and make sure both sides come out. sometimes on cheaper brakes only one side will move increasing the risk of unseating the piston.

Then remove/cut the lines at the handle and run the lines. be quick and try to keep open end up so very little fluid drips out. keep both open ends UP so fluid does not keep dripping. If line is cut ALWAYS use a new olive. Then reattach the lines to brake handles and use a brake spreader or screwdriver to puch pistons back in caliper. This pushes any air back in to reservoir. I have done it 100's of times and it works 99% of the time. Sometimes depending on the system you need to add a tiny bit of fluid afterwards but most thew time its good to go.
Thanks for response. Curious to understand; Does this shift some fluid to the caliper so when the hose is cut there is less to leak out or that pushing the calipers back in afterwards forces the trapped air into the levers where it can escape by opening the fill screw?
You dont have to open the fill screw unless you screw around and shake it out of the hose or leave the handle wher it can drip. Hook up the line put the pads back in and mount caliper on the rotor, pump the brakes and they should feel fine.
If you think you can handle 10,000 feet then check out this ride...[/size][size=150]http://www.michiganmountainmayhem.com

apctjb
Posts: 59
Joined: Mon Oct 30, 2017 11:27 pm

by apctjb

Thanks for all the great advice. New brake set arrived and I made the switch no problem, only took a couple of minutes. Easy!

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