How do you 'repressurize' break fluid after a full drain? (Just replaced SMC).

[Chuckles]

I just replaced my SMC. I don't know why I was putting it off, it wasn't that hard. At someone elses recommendation, I did a full bleed in the order outlines in the service manual of all 6 bleed points on the Calibers and the Proportional Control Value. I'm glad I did. It was quite yellow and I pushed through everything to get good clear fluid from all points. Then, when removing the SMC, I of course had to drain the lines that lead to the front left caliper.

Everything is back together and I'm going back through the bleeding process, obviously with a lot of air in the system, and my front master doesn't seem to be pressuring anything. It's not pushing any fluid out at all. Is there a trick? I have confirmed that I only have one bleed valve open on my front caliper attached to the SMC. Thanks for tips.

 

[Chuckles]

Nevermind, I figured it out. I just had to pump slow and methodically paying attention to the wetness of the mastery cylinder. Not fast and furious like a rabbit on another rabbit. I seem to remember some past girlfriends giving me similar advice.

 

[Kevcules]

Good to hear you got it figured out. I'm going to change mine soon also.... Any advice other than the jack rabbit approach?

 

[Chuckles]

Well, I bled the system twice because I had a messed up SMC. I was just going to replace the SMC then bleed, but someone pointed out that the SMC has a screen and of course that tiny return pressure hole that could clog with brake system snot, so I bled to get everything good and clear in the system, hopefully carrying out system snot, then replaced the SMC, then bled the system again. IGoFar recommend this for bleeding the system and I have to tell you, it's a cheap lifesaver.. (https://www.motionpro.com/product/08-0143) You don't need a 2nd person to bleed with it. Buy extra fluid because you'll need to waste a lot by running it through the system then back out the other side. You don't want to reuse any of that. Have a few plastic water bottles for capturing and observing the fluid. 8, 10 and 12 mm wrenches. And that's it. Someone suggested purchasing new master cylinder gaskets (I'm not sure what they are called) and replacing them with every change. I did not do this, but might consider it. They cannot be very expensive. And keep the brake fluid off your paint - have lots of rags handy. You might even want to go to your hardware store to buy some extra tubing for the training.

It took me all day today. If I were to replace the SMC again and bleed the system, I could do it in an hour with minimum fuss.

Shout out to IGoFar for the excellent advice!

 

[Kevcules]

Sounds good. Did you replace the crush washers? Are they 8mm?

 

[Chuckles]

Sounds good. Did you replace the crush washers? Are they 8mm?

I did replace the crush washers on the SMC because IGoFar adviced me to purchase them. I would not have otherwise. I guess they are soft and ensure good sealing with the high pressures that may occur inside the brake system. You'll know you screwed up if you don't change them, use the bike, and see stains.

 

[SMSW]

You can save some brake fluid by using a turkey baster to suck out the old juice in the Front and Rear Master Cylinders, then refill them before doing any bleeding. Now when you start the process you will be drawing fresh fluid into the lines from the first pump of the lever. Watch out for baster drips! Cover all painted surfaces near where you will be working with plastic and something absorbent over the plastic to prevent dripping.

 

[Chuckles]

You can save some brake fluid by using a turkey baster to suck out the old juice in the Front and Rear Master Cylinders, then refill them before doing any bleeding. Now when you start the process you will be drawing fresh fluid into the lines from the first pump of the lever. Watch out for baster drips! Cover all painted surfaces near where you will be working with plastic and something absorbent over the plastic to prevent dripping.

Well, I did, kinda. I asked my wife 'where the hell is our turkey baster'? She told me I used it for for something. So I used my ear sucker ball. It worked fine. It's also useful because it can pull solids out of the master reservoirs.

 

[mello dude]

You can save some brake fluid by using a turkey baster to suck out the old juice in the Front and Rear Master Cylinders, then refill them before doing any bleeding. Now when you start the process you will be drawing fresh fluid into the lines from the first pump of the lever. Watch out for baster drips! Cover all painted surfaces near where you will be working with plastic and something absorbent over the plastic to prevent dripping.

I do this on a yearly basis, it does help keep things clean to when its time to do a full fluid replacement...

 

[Chuckles]

I do this on a yearly basis, it does help keep things clean to when its time to do a full fluid replacement...

I think that's a good idea, and it's so easy that it doesn't have to be avoided.

My kids bought me my dream bike (an ST1300PA Police Bike) for my 57th birthday. The bike runs great, but has a few issues. I'm so thrilled by my kids effort that I cannot complain that they didn't know exactly what to look for. IGoFar told me the common story - Police Departments get the bikes and the car mechanics take care of the bikes, but don't understand the subtleties and complexities. Then, when the bike is retired, the PD's just slide some cables used for lighting and radios and put the bike on the auction block. Well, my bike is in great condition for a bike with 55K miles on it and I'll learn to work around the faults. It's faster than a scaled cat and the breaks have been the only problem so far. Now, I need to super tweak it. I'm thinking about painting it yellow!

 

[jfheath]

Larry probably already mentioned it - but rather than just pumping slowly, it can be more productive to keep the bleed valves closed, pump a few times in quick succession, hold the lever / pedal to keep the system sealed, and release the bleed valve, and close it again just before the fluid stops flowing. This lets the built up pressure push the fluid through. Just pumping can suck the air / fluid back so its difficult to build up any pressure - so it takes longer.

The non return bleed valve is a good tool to have, but its handy to have a few tricks up your sleeve.

 

[SMSW]

Well, I did, kinda. I asked my wife 'where the hell is our turkey baster'? She told me I used it for for something. So I used my ear sucker ball. It worked fine. It's also useful because it can pull solids out of the master reservoirs.

I give up, what's an ear sucker ball?

BTW, its probably not a good idea to use kitchen tools for food again after they visit the shop.

 

[Chuckles]

I give up, what's an ear sucker ball?

BTW, its probably not a good idea to use kitchen tools for food again after they visit the shop.

These things...

https://www.amazon.com/Hand-Bulb-Ear-Syringes-oz/dp/B000LX4L4M

I call them "Ear cleaner balls" or "Snot suckers"

 

[Andrew Shadow]

If a brake system has been completely drained of fluid, including the master cylinder, it is usually beneficial and faster to bleed the master cylinder first. Then leave the bleeders valves open for a while to allow gravity to get some fluid in to the lines, before attempting to bleed the system.

 

[mello dude]

I think that's a good idea, and it's so easy that it doesn't have to be avoided.

Don't forget to do the clutch too.....also I check the interior of the reservoir and clean that with paper towels if needed.

 

[northwestparider]

Years ago I adopted the single squeeze/pump method for bleeding brakes. One stroke hold it and open the bleeder. The guy that hold me about it says that doing it this way doesn't break any large air bubbles into smaller ones. It has worked well for me even when replacing a whole system on a car (everything from the master to the wheel cylinders).

 

[Barry Batkin]

I just replaced my SMC. I don't know why I was putting it off, it wasn't that hard. At someone elses recommendation, I did a full bleed in the order outlines in the service manual of all 6 bleed points on the Calibers and the Proportional Control Value. I'm glad I did. It was quite yellow and I pushed through everything to get good clear fluid from all points. Then, when removing the SMC, I of course had to drain the lines that lead to the front left caliper.

Everything is back together and I'm going back through the bleeding process, obviously with a lot of air in the system, and my front master doesn't seem to be pressuring anything. It's not pushing any fluid out at all. Is there a trick? I have confirmed that I only have one bleed valve open on my front caliper attached to the SMC. Thanks for tips.

Did you manage to bleed the system on your own? It looks like a two man job to me.

 

[Chuckles]

Did you manage to bleed the system on your own? It looks like a two man job to me.

Oh yes, it was very easy. I ordered this tool...

Hydraulic Brake Bleeder - Motion Pro

at the recommendation of IGoFar here. It's super simple to use. A one way value that lets you bleed by yourself.

 

[Barry Batkin]

Oh yes, it was very easy. I ordered this tool...

Hydraulic Brake Bleeder - Motion Pro

at the recommendation of IGoFar here. It's super simple to use. A one way value that lets you bleed by yourself.

Yes I have bought one of those. Did you use it with a vacuum pump, or just straight into a jar?

 

[Obo]

Yes I have bought one of those. Did you use it with a vacuum pump, or just straight into a jar?

Straight into the jar is how you'd normally use it.