Another front brake question

Having not found anything on this question at this time. Just bought a 2007 ST1300 with 33,000 miles, in need of front brake pads.
Never worked with Linked Brake System before. Do I have to remove some of the brake fluid of the rear brake
canister, as I do the front master cylinder. This is before pushing in the caliper pistons after cleaning.
Thank you, Bobby

The assumption is the fluids were filled when the pads were new... so, no need to remove or add any... just clean the pistons, push them in a little to give you the needed clearance, install the new pads.

The brake fluid has been changed since the last pad change. So I need to take some fluid from both, right.
Bobby

waterboy2 said:

The brake fluid has been changed since the last pad change. So I need to take some fluid from both, right.
Bobby

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Maybe... I always tried to time my fluid changes with my brake pad changes... I would go ahead and take a little just so if it is at full capacity you won't spill any on surfaces that it will ruin.. maybe just a small bit.

This will not push some bad back though the Secondary Master Cylinder?
Bobby

No, the fluid you have is what you have... so if you feel it's time to do the bleed then do that... don't worry too much about it. As long as you flush the brake fluid in a timely manner as dictated by the service interval or sooner if you are in extreme climates then you should be just fine.

I have read about getting contaminates back in the SMC.
Bobby

waterboy2 said:

I have read about getting contaminates back in the SMC.
Bobby

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Then don't do it, use all new. Wipe out the reservoir and clean the rubber bellows with denatured alcohol.

waterboy2 said:

I have read about getting contaminates back in the SMC.

Click to expand...

The SMC operates the Rear Caliper. You are not going to effect that circuit when replacing front pads.

Kevin_56 said:

The SMC operates the Rear Caliper. You are not going to effect that circuit when replacing front pads.

Click to expand...

As Kevin said, no fluid exchange between front and rear. However when you push in the front pads-piston you are also forcing fluid back into the REAR reservoir as the front center pistons are ran by the rear brake circuit so the rear reservoir may fill a bit.

Thanks Ziamon, that was what I was wanting to know.
Bobby

Take a look at my article here : Link - it is intended for issues related to bleeding the brakes, but the diagrams also help to show which pistons are connected to which lines and reservoirs. The images are shown in better resolution in the pdf link in post #1.

Thanks for posting that John, I just got off the white courtesy :call: with our new friend.
Don't you just love helping folks :mcrider:

jfheath said:

Take a look at my article here : Link - it is intended for issues related to bleeding the brakes, but the diagrams also help to show which pistons are connected to which lines and reservoirs. The images are shown in better resolution in the pdf link in post #1.

Click to expand...

Wow thanks for that link. Nice pdf. I guess I missed that when posted the first time around. Great job!

Igofar is the man. I wish I knew just a little of what he know a lot about.
If you need help just call on Larry, he will get back to you. Thanks again
Larry for the help.
Bobby

waterboy2 said:

Do I have to remove some of the brake fluid of the rear brake
canister, as I do the front master cylinder. This is before pushing in the caliper pistons after cleaning.

Click to expand...

It is considered bad form to force brake fluid back from the brake caliper to the master cylinder.

A better method is to open the bleed screw when pushing in the caliper pistons, this dumps the brake fluid along with any sediment/contaminates that may have accumulated in the brake caliper.

In addition this method alleviates any concern of overflowing the master cylinder reservoir, which I think applies to your particular situation, that of adding brake fluid with worn brake pads still installed in the caliper.

Anna'sDad said:

It is considered bad form to force brake fluid back from the brake caliper to the master cylinder.

Click to expand...

I've read something to this effect before, and I don't understand why this should be so. The compensation port is tiny, so the return of the pistons is slow, but I can't see that anything would be damaged by doing it. But, generally speaking if I am doing owt with the brakes, I'll be flushing through and replacing fluid via the bleed valves.

But I like to get a feel for how easily the pistons move and get a good idea about whether or not the route to the compensation port is clear, so after doing a full clean, flush and bleed, I will generally pump the piston out part way and push them in again to verify that everything is moving and flowing as it should.

Your point about flooding the reservoir is a good one. I only ever did this once on my ST1100ABS. I'd forgotten that I had previously renewed the fluid without needing to replace the pads, so there was too much fluid in the reservoir when I eventually put in new pads. In fact it turned out that there was too much fluid in the system and a couple of days later, when I turned on the ignition, I got warning lights and the customary whirr of the ABS modulator didn't happen. I didn't associate this with my new pads, but the fuse for the ABS modulators had blown - presumably because they were unable to turn. I bled some fluid from the callipers, until the reservoir level was correct, replaced the fuse, held my breath and all was OK again.

I've not made that mistake since !

I'm not sure Mellow's advice is right for all of us, and I would lean more toward what John and Anna's Dad say. I have routinely bled and changed my brake fluid between pad changes. And naturally, I fill the reservoirs to the fill line or maybe to the top limit if the brake reservoir has a max and min line (cars). In this instance, pushing the pistons back into the calipers at pad change time might easily overfill the master cylinder(s) reservoir(s).

Certainly, if Mellow can run through a set of pads in the two years Honda posits between fluid changes, then sure, no additional brake fluid has been added and it will all go back from whence it was dispensed.

Having twice completely rebuilt my old Guzzis' brake systems (calipers, flexible brake lines, etc.) you might say I am now a born again brake fluid bleeder. I'd rather do it by the book or more often than go through the time and expense of replacing expensive parts.