inconsistent breaking...

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Jimmy8998
Posts: 14
Joined: Sun May 24, 2020 7:02 pm
My Bike: ZXR400L
Location: Plymouth

inconsistent breaking...

Post by Jimmy8998 » Fri Oct 09, 2020 1:27 pm

hello everyone,
I have a 1993 ZXR400 its my absolute pride and joy but I've been having some problems with the breaking recently.
They are an arsehole to try bleed and when I think I have it right they just aren't what they should be... they are un responsive and soft not sharp and precise how they should be.
I've tried a couple different techniques and I've read through different threads on here to ensure there's nothing I've missed.

so to the problem... apart from the fact they aren't as good as they should be I've encountered a new problem this is that when I do a slow continuous squeeze of the break leaver f**k all happens, there's no stopping power whatsoever... if I apply a firm, sharp pull to the leaver it stops dead...
my immediate thought is air... how ever after bleeding for hours and going through bottles of fluid I'm reluctant to settle on that decision.

has anyone had this problem and what was you solution?

many thanks.

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banner001
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Posts: 2496
Joined: Sat Sep 24, 2011 3:27 pm
My Bike: ZXR400 L4
Location: Nuneaton

Re: inconsistent breaking...

Post by banner001 » Fri Oct 09, 2020 2:48 pm

Sounds like you need to rebuild your master cylinder
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003

User avatar
Jimmy8998
Posts: 14
Joined: Sun May 24, 2020 7:02 pm
My Bike: ZXR400L
Location: Plymouth

Re: inconsistent breaking...

Post by Jimmy8998 » Fri Oct 09, 2020 3:12 pm

I've done that, all new oem parts...?

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Jimmy8998
Posts: 14
Joined: Sun May 24, 2020 7:02 pm
My Bike: ZXR400L
Location: Plymouth

Re: inconsistent breaking...

Post by Jimmy8998 » Fri Oct 09, 2020 3:13 pm

I guess another look wouldn't hurt though

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banner001
Track day God
Track day God
Posts: 2496
Joined: Sat Sep 24, 2011 3:27 pm
My Bike: ZXR400 L4
Location: Nuneaton

Re: inconsistent breaking...

Post by banner001 » Fri Oct 09, 2020 5:59 pm

Did you rebuild the calipers. Have you kept the cable splitter near the horn. Have you tried reverse bleeding. Did they ever work? Front or back brake issue?
UK ZXR400 L3 (1993) - Fully restored and on the roads, my green beast!
JPN ZXR250 A2 (1990) - Revs to 19,200rpm... 'nuff said :smt003

User avatar
Jimmy8998
Posts: 14
Joined: Sun May 24, 2020 7:02 pm
My Bike: ZXR400L
Location: Plymouth

Re: inconsistent breaking...

Post by Jimmy8998 » Sun Oct 11, 2020 2:51 pm

I have rebuilt the callipers for a clean and a check. however I didn't remove the pistons. the splitter is gone. it has steel lines accompanied with nissin callipers off of the Honda CB1300. I tried reverse bleeding the other day with a med syringe, it has worked well. the breaks have never been 100%. its a front break issue.
So decided to rebuild the MC as sugested. I've done this before, it was my third step in troubleshooting sequence. when the new MC kit came it was exactly the same however it came with a washer that wasn't already in the MC... I decided to use the washer after checking on youtube and such and seeing it being installed on there.
I rebuilt the MC yesterday and on a closer inspection realised the washer was hindering the retaining washer from seating properly! so i wasn't getting the correct seal. I've removed the seal and touch wood the breaks seem firm and feel good.

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