I know this really doesn't answer your questions, but the last time I flushed all of the old brake fluid was on a previous GMC Envoy that had 148k on the odometer. I bought a set of speedbleeders and put them on each caliper. I attached a drain hose and catch container to each, loosened all of them at once, pumped the brakes and kept refilling the master cylinder every few brake pedal pumps. Once I went through a large container of new brake fluid, I made sure the master cylinder was filled to the same spot when I started and tightened everything back up. Easy-peazy. Did it myself and I didn't even have to remove the wheels. The speedbleeders can even stay on the calipers for future use.

 

That is not the recommended process for the twins.

OP, do a search and you will find the thread that tells the proper bleeder sequence. I would invest in a cheap power bleeder that will flush the fluid from the master cylinder through the entire system.

 

The little bit of fluid that is in the MC, that you want to take out with the turkey baster is not worth fooling with. A few extra pumps will remove that while chasing it out with fresh fluid. A hose on each bleeder hung in a container with fluid works well but you will need the wheels off. A pressure bleeder works best but not many people have them.

 

Thanks
Why would I need the wheels off (considering that I can reach the bleeder nipples with the wheels on). Is there something else I would need to access ?

 

I doubt that you can reach the bleeders with the wheels on, because if I remember correctly, there is an inner/outer bleeder on the front calipers.

 

Brake fluid change - push or pull?

It's that time, 36k miles on my 2017 and time to change the brake fluid. For you guys who have done this already on this gen truck, does it work better to pull the fluid through with suction or push it through with pressure on these particular trucks? I've got a vacuum oil extractor that I can...

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Read post #14.

 

You can buy a Motive Products power bleeder for $50, be the best money spent.

 

I figure with about 50K miles on the odometer, it's time to flush the brakes (they feel a bit soft)

Unless you somehow let the fluid in the reservoir get low, or did some work on your brakes, it's very unlikely you need to flush your brake fluid. Old brake fluid won't make the pedal feel soft, unless there's moisture in the fluid and you get the brakes very hot where the water starts to vaporize. Moisture getting into the fluid is more a result of time than miles, and is likely dependent on location and activities. It can be tested.

 

If people would stop playing with the cap on the master and looking in there it can't get moisture it it.
50k miles? not me, but I guess I live on the edge.

 

Thanks, I found a pic that shows the outer and inner bleed screw . Makes sense now

 

Depending on wheel type, no need to remove them. Just jack front up and spin wheel till you can see it.
p

 

Depending on wheel type, no need to remove thrm. Just jack front up and spin wheel till you can see it.
p

I wouldn't want to get brake fluid on my wheels.

 

My experience with bleeding is that air can seep around the loosened bleeder nipple threads and come up the line, especially on "speed bleeders". And that same air seepage can fool you doing a vacuum bleed, looking like there's air in the line.
To avoid these problems, don't use DIY shortcuts. Use a pressure system that pushes fluid in the direction it's meant to go. That includes the old 2 man pedal pump and bleed. For a full bleed when air has been introduced, a power bleed will save everyone a lot of grief.

 

I actually didn't realize that our calipers had dual bleeders. Learned something new today....

I'm currently at 37k now and I was planning to flush the brake fluid at/around 50k. Could be excessive at 50k, but it's simply peace-of-mind for me.

 

If you can't get the turkey baster in, on other cars I've used one of the screw top hand pumps often used for diff fluid and such, has a smaller tube that can get farther down the master to get more out. But as noted a little old fluid isn't going to be an issue and I'm just overly anal about it.

And yes a fixed caliper style like ours, or a Brembo, will usually have 1 bleeder per caliper side as opposed to typical floating caliper with just one for the whole unit.

 

There is nothing wrong with proactively flushing your brake fluid. Regardless if the cap is open or not you will have less moisture in new fluid than you would in 2 year old fluid. Do it, the nipples will thank you by not seizing up. Don't go tighter on them than you need when your done.
Always start at the wheel furthest away from the master and flush that one until it runs clear, then go to the other rear, then right front then the shortest run last. I try to flush at least every 2 years on everything I own with brakes and it is a notable improvement in petal feel each time on each vehicle.

 

There is nothing wrong with proactively flushing your brake fluid. Regardless if the cap is open or not you will have less moisture in new fluid than you would in 2 year old fluid. Do it, the nipples will thank you by not seizing up. Don't go tighter on them than you need when your done.
Always start at the wheel furthest away from the master and flush that one until it runs clear, then go to the other rear, then right front then the shortest run last. I try to flush at least every 2 years on everything I own with brakes and it is a notable improvement in petal feel each time on each vehicle.

I do the same, bleed every two years. Brake fluid is hygroscopic, so bleeding on a schedule is a good thing.

 

Best to flush in the order that is recommended in the Service Manual with ABS brake system.

 

Could you could plan this job at the same time as a tire rotation? I'm not sure exactly how that would work with the order to bleed. But I do a rear differential change at the same time as a tire rotation because you need to lower the spare tire to drain the fluid.

 

For what it's worth, the DOT4 fluid that I bought did declare on the bottle that it was "rated" for 50000 miles

 

Supposedly DOT 4 should only be used after completely flushing all the DOT 3 out.

 

Not supposedly, ABSOLUTELY!

 

No mixing fluids, and I thought (check me on this) it was best to have all new components if swapping fluid types. I went to DOT5 On my Harley because I had all new parts- just not positive it’s required to have all new parts to change types on from 3-4 (I wanted the dot5 because it’s supposed to be less likely to eat finishes)

 

Dot 5 or Dot 5.1? Big difference.

 

Just seems like it would be kind of hard to flush an ABS brake system completely.

 

If of interest:

How to: Bleed Brakes with pressure bleeder

All, Disclaimer: I am not an engineer and I am not responsible for any modifications you make to the vehicle as a result of this guide. Use at your own risk/discretion. Obligatory not affiliated with these companies, I bought all of this myself, none of it was provided to me, etc... Time...

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DOT 5 doesn't absorb water so air bubbles will stay bubbles and rust where they sit. Its important to completely flush a DOT 5 when you do work, so it comes with purple dye to help with that. I have a 04 Sporty and as far as I know, HD used DOT 5 only that year. I have a bad rear brake switch to show why.

 

I love this site- always learning here.
well hopefully she lasts a while, but at least I built it lol so I can fix this thing. I used a vacuum bleeder which was awesome and bench bled the master etc but it’s highly probable small bubbles will always exist in the system.

 

DOT 3 and 4 are compatible but definitely don’t mix DOT 5.

 

Performed the flush this evening as per procedure using the old school Gatorade bottle method rather than using a vacuum bleeder . Only place I messed up was doing both rear brakes before the fronts . In any case , I got clear fluid out of all bleeder screws at the end so it's all good .

The old fluid was medium amber / honey colored as opposed to the clear / pale yellow new fluid ( I eventually decided to use DOT 3)

 

 

Nothing wrong with dot 3, the difference is it needs to be flushed more often but generally has a higher dry boiling point than 4 since Ford had a giant screw up in the service 80's. Anyways, does it feel better? It should!