Right brake disc gets hotter than the left one

[M0rf3M]

Hi there,

I'm running out of ideas so I decided to shoot a question: am I over concerned about the fact that right front brake disc gets hotter than the left one after hard braking?

 

It seems that the right caliper's brake pads do not retract as much as the ones in the left caliper.

 

Things checked/done:

1. brake calipers are clean
2. brake caliper pistons move freely (by hand)
3. brake disc (OEM) does not seem warped - brakes are not pulsing under hard braking
4. brake fluid replaced 1 year ago
5. front wheel turns (min 2 turns)
6. wheel axle seems straight - bike goes straight

 

Or should I just take the brake calpier apart clean it fully, replace orings and replace brake fluid?

[Presson]

Your diagnosis sounds spot on. I would recommend a full overhaul and I would do both, not just the RHS. When you take the pistons out check them for pitting and corrosion and if warranted replace them. Have a good look at the caliper bores as well and make sure they are all meticulously clean. Replace the seals too.

 

You probably know this already, but it can be difficult sometimes to get air out of the line that goes over the mudguard to the LH caliper. Bleed that one by holding it on the RHS of the bike ( speed bleeders or another pair of hands helps).

 

I don't have access to an airline. So if it helps I found the easiest way to get pistons out was by mounting the caliper in a workmate vice and using a cycle track pump with a ball inflator attached and a large wiring grommet placed into the port. Just enough pressure to move the pistons without them flying out. Use a piece of wood/ straps or zip ties to isolate each piston and keep a note of their positions. Use red rubber grease.

[Thumbs]

Those Nissan brake pistons are renowned for rusting, Powerhouse sell stainless steel ones 

 

I replaced mine when the bike was 2 years old with 18k on and they were starting to pit then 

[Terry]

Just as a counter viewpoint; a hotter brake mean that disc is doing more of the stopping as kinetic energy is converted to heat through friction.

 

So you should be asking why the left disc is colder, as this is not delivering as much braking force as the right.

 

When you clean the pistons I recommend removing the seals (if you're careful they are reusable) and cleaning their grooves carefully as corrosion and dirt get in there and increase the friction on the piston.

[Presson]

Hmm, Terry makes a good point. The problem could be as simple as a bit of air in the link pipe to the LH caliper that runs over the mudguard. Maybe try bleeding that again with the caliper off as I suggest in my other post above. If it's that then you'll know. 

 

You didn't say what year the bike was and as Thumbs points out the pistons have a tendency to quickly corrode so I would still be inclined to do a full overhaul anyway; safety first.

[V4 Rosso]

It' s been a while since I had a VTEC, but isn' t this because of DCBS? When applying front brake only the right caliper has 3 active pistons and the left only two.

[Captain 80s]

1 hour ago, V4 Rosso said:

It' s been a while since I had a VTEC, but isn' t this because of DCBS? When applying front brake only the right caliper has 3 active pistons and the left only two.

 

Topic is in "Eighth Generation VFR's"...  no DCBS.  Additionally, how could a 6 piston caliper have 3 active pistons?  Linked Brakes would be even worse than I thought, if that is even possible.

[M0rf3M]

Thank you v.much for your valuable input - much appreciated.

 

On 7/5/2024 at 11:11 AM, Presson said:

You probably know this already, but it can be difficult sometimes to get air out of the line that goes over the mudguard to the LH caliper.

 

Indeed, trapped air in that line is my primary suspect.

 

On 7/6/2024 at 3:26 AM, Terry said:

Just as a counter viewpoint; a hotter brake mean that disc is doing more of the stopping as kinetic energy is converted to heat through friction.

 

So you should be asking why the left disc is colder, as this is not delivering as much braking force as the right.

Good counter argument - love it! Maybe a full overhaul of both calipers is the way to go.

 

On 7/5/2024 at 1:30 PM, Thumbs said:

Those Nissan brake pistons are renowned for rusting, Powerhouse sell stainless steel ones

Cheers - I'll take a note of that. I inspect and clean calipers each winter, they did not seem corroded the last time I've checked.

 

On 7/9/2024 at 7:54 AM, Presson said:

You didn't say what year the bike was and as Thumbs points out the pistons have a tendency to quickly corrode so I would still be inclined to do a full overhaul anyway; safety first.

2015 🙂