Soft rear brakes after tire change, why???

[johnny-canuck]

So, after 22,000 Kms (13,700 miles) and a bunch of canvas showing all the way round, I decided to change the rear tire.   I should have changed it a bit sooner, but even so, I am impressed with the mileage I got out of the Exedra.

Now to my problem.  When I picked up the bike which was still sitting in the mechanic's stall, the rear brake pedal went all the way to the bottom.  After a few pumps it came up but was still soft.  The shop was closing so I left and figured it would come around.  I rode it home, about 5 miles, and the rear brake is still soft.   The front brake seems to work fine, but the rear is soft and I don't think I'm getting full braking power.  I don't know why the brakes would be affected as other than take the caliper off, the brakes aren't touched.  It feels like air in the line, but the lines weren't opened so no air should get in.

It's pouring rain today, so I haven't got out to really try it.  I'll take it out tomorrow for a run and then back to the shop on Monday if they don't improve. 

My question is:  Has anyone had this happen to them?  

[johnny-canuck]

Forgot.  It's a 2018 Venture TC.

[cowpuc]

I have absolutely zero idea if this is even remotely related to what you are experiencing but can tell you for a fact, I have seen very similar things happen in the back room of my shop a few different times.  One example I can think of is having one of my employees working on a scoot, doing wheel bearings so the caliper is hanging from bungee cords. Another employee comes up and starts yapping and while he is yapping the brake lever gets activated enough (why someone would play with squeezing a brake while chatting I have no idea) to force the pads out and empty the master putting air in the system.. The mechanic doing the job thought it was odd that the pads were out when he went to put the wheel back on but didnt think past just forcing the pads back in and putting the caliper back on,, problem solved,, right?? Wrong.. Ended up having to bleed the system to get the air out of it AND,, this was on a system that liked to capture air at the high point (IMHO,, this is common but many really good mechanics do not agree with me on that) which required some tedious bleeding from banjo fittings and leaning the bike just right..  I know,, getting long winded here but I  really did want to let you know/answer your question concerning whether or not any of us clubbers have ever heard of such a thing. Bottom line,,, it happens IMHO. Maybe take it back in and let the dealership deal with it? Puc 

[ChiefGunner]

23 minutes ago, cowpuc said:

I have absolutely zero idea if this is even remotely related to what you are experiencing but can tell you for a fact, I have seen very similar things happen in the back room of my shop a few different times.  One example I can think of is having one of my employees working on a scoot, doing wheel bearings so the caliper is hanging from bungee cords. Another employee comes up and starts yapping and while he is yapping the brake lever gets activated enough (why someone would play with squeezing a brake while chatting I have no idea) to force the pads out and empty the master putting air in the system.. The mechanic doing the job thought it was odd that the pads were out when he went to put the wheel back on but didnt think past just forcing the pads back in and putting the caliper back on,, problem solved,, right?? Wrong.. Ended up having to bleed the system to get the air out of it AND,, this was on a system that liked to capture air at the high point (IMHO,, this is common but many really good mechanics do not agree with me on that) which required some tedious bleeding from banjo fittings and leaning the bike just right..  I know,, getting long winded here but I  really did want to let you know/answer your question concerning whether or not any of us clubbers have ever heard of such a thing. Bottom line,,, it happens IMHO. Maybe take it back in and let the dealership deal with it? Puc 

I would agree with @cowpuc on this.

You didn’t have the “mushy” brake before you took it in and did after they did the job.

i replaced my pads at about 43k miles, but I probably didn’t need to. Still had half the pad thickness left, but I did go with EBC and not OEM. Reason for that was 4-6 weeks waiting for OEM pads! Not in stock?? I guess they don’t plan on anyone needing a common item.

  Point I’m making is that I had no problems when done and didn’t have to bleed anything.

They messed it up, have them fix it.

[BlueSky]

I recently had an issue with my rear brake going soft and then not working at all on my 07 RSV.  Turned out the diaphragm in the top of the reservoir had fallen to the bottom and was blocking fluid from gravity draining to the master cylinder.  

[johnny-canuck]

Thanks to all for the input and to cowpuc for the detailed reply.  Just shows how easily things can get messed up.  I'm taking it for a ride today, but will definitely be taking it back to the dealer.  Even though I didn't buy the bike there, they are treating me really good.  Part of the problem is that this is a relatively small city and as far as I know, there is one other TC and one Eluder in town, so they don't get a lot of practice.

[cowpuc]

On 10/18/2020 at 9:24 AM, johnny-canuck said:

Thanks to all for the input and to cowpuc for the detailed reply.  Just shows how easily things can get messed up.  I'm taking it for a ride today, but will definitely be taking it back to the dealer.  Even though I didn't buy the bike there, they are treating me really good.  Part of the problem is that this is a relatively small city and as far as I know, there is one other TC and one Eluder in town, so they don't get a lot of practice.

You are welcome Johnny, anytime!! Hope you get er figured out!!

[johnny-canuck]

Been busy lately.  The weather this month has been fantabulous!!!  It's like living in California instead of the East Coast of Canada.  Riding almost everyday.  But it looks like that has come to an end.  Rain and cold weather in the forecast

The brake issue worked itself out after a couple of days of riding.  Not sure what was going on.  I did talk to the mechanic and he has no idea.  The issue I'm finding with this bike is that there are so few of them that the techs don't know much about them.