Going to do some brake work and would like to change the fluid also.
I didnt plan on removing all the fluid just about all of what would be visible in the master cylinder.

Do I need to bleed the system after refilling the master cylinder or would they be OK as long as all the fluid isnt removed?

I would bleed em..better safe than sorry...I always say..:D

I would definantly advise bleeding the brakes afterwards... actually I would advise changing the all brake fluid if you are going that far... but that is just my opinion.:)

x2

yes you have to bleed them, so just run a bunch of fluid thru the lines as you are bleeding. You will not get all the fluid in the calipers, but you will get a lot of it

Thanks for the replies. I was afraid that would be the answers. Reason being, the bleeders on my calipers, except for the caliper I replaced, look like they arent going to budge.
The truck was a NY/Canada truck before I bought it so the road salt sort of did it's thing to some things under the truck.

For the $50 per caliper (after core trade-in) maybe my next thing will be changing the other 3 calipers.

yep ..agreed ...bleed them

Thanks for the replies. I was afraid that would be the answers. Reason being, the bleeders on my calipers, except for the caliper I replaced, look like they arent going to budge.
The truck was a NY/Canada truck before I bought it so the road salt sort of did it's thing to some things under the truck.

For the $50 per caliper (after core trade-in) maybe my next thing will be changing the other 3 calipers.

Drench the bleeders in PB blast or similar pentrating oil, and then just before leaning on the wrench, repeatedly rap the top of the bleeder with a ball peen hammer to break loose the threads. Hit it pretty hard, but obviously not hard enough to deform the bleeder. Also, use a 6 point wrench NOT a 12 point wrench

Somebody correct me if I'm wrong, but to get a full bleed, isn't a Tech-II needed to cycle the ABS system?

Somebody correct me if I'm wrong, but to get a full bleed, isn't a Tech-II needed to cycle the ABS system?

yes, for a 100% system bleed.

You don't need to bleed the system if you just replace the fluid in the reservoir. If you do I would change it every week for 3 weeks to get more of the old crap out, but flushing the whole system would be better.

I’ve bled my system twice with the Motive Break Bleeder. Works great.
http://www.motiveproducts.com/02bleeders.html
With a turkey baster, remove all fluid from reservoir, add new fluid, install bleeder over reservoir, and pump up to 10 PSI. Go to each wheel and bleed until new fluid is present. Only about ½ of reservoir capacity is needed for bleeding. Motive Bleeder is only used as a pressure source, so there’s nothing to clean.
I use the ATE DOT 4 fluid, and alternate between the gold and blue fluid. Bleeding is obvious when the new, different colored fluid is draining. Do NOT use DOT 5. You'll need about 1.5 liters of fluid.
http://www.motiveproducts.com/04fluids.html

Buy new bleeder fittings before you start and replace them. Loosening these with a 6-point box wrench or socket to avoid rounding fitting.

I’ve bled my system twice with the Motive Break Bleeder. Works great.
http://www.motiveproducts.com/02bleeders.html
With a turkey baster, remove all fluid from reservoir, add new fluid, install bleeder over reservoir, and pump up to 10 PSI. Go to each wheel and bleed until new fluid is present. Only about ½ of reservoir capacity is needed for bleeding. Motive Bleeder is only used as a pressure source, so there’s nothing to clean.
I use the ATE DOT 4 fluid, and alternate between the gold and blue fluid. Bleeding is obvious when the new, different colored fluid is draining. Do not use DOT 5. You'll need about 1.5 liters of fluid.
http://www.motiveproducts.com/04fluids.html

Buy new bleeder fittings before you start and replace them. Loosening these with a 6-point box wrench or socket to avoid rounding fitting.

I can tell you from experience that if you use DOT 5, you will end up rebuilding all your calipers, and god knows what would happen to the ABS pumps and valves. DOT 5 does not mix with DOT 3, and the stuff will congeal and collect in all the hydraulic system cavities, doing bad things to your braking performance.

That was my experience, anyways

Modified has the right idea I bought one of those brake bleeders from summit and love it. It beats pumping the brake petal. You should flush your brake fluid every few years it collects water and can corrode the ABS system

I second what modified said. Easy to bleed brakes with that tool.

Even though we currently have over 15 feet of snow at the 3400 foot level, salt is not used on our roads. My bleeder fittings were like new.

I am glad I no longer live in Illinois or Wisconsin where I spent my younger years. My days of watching the road pass by through the holes in the floor boards are over.

How about a Dot 5.1 brake fluid...anyone with experience with it...is it that much better and worth the cost?
http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml

How about a Dot 5.1 brake fluid...anyone with experience with it...is it that much better and worth the cost?
http://www.stoptech.com/tech_info/wp_brakefluid_1a.shtml


I've used DOT 5.1 in my off road motorcycles for several years. While I had my brakes go away easily with DOT 4 (especially the rear brake), DOT 5.1 really took some hard work to fade. DOT 5.1 is fully compatible with DOT 4 and DOT 3. Big drawback is price. I pay about $10/pint. Not a big deal when a pint is good for several front and rear changes. A big deal when you need quarts to do a fush. My conclusion was that is was worth it on my motorycle, but not in my cars. I use a good DOT 4 synthetic in my cars (Valvoline )

what size wrench to use on bleeders and any sequence to follow as to which wheel to bleed first etc.?

suck the brake fluid out of the reservoir first to within 1/8' of the bottom then fill with new fluid, and start bleeding with clean fluid.

drive safe good luck

what size wrench to use on bleeders and any sequence to follow as to which wheel to bleed first etc.?

10mm 6-point box wrench works best to prevent rounding corners.
Buy spare bleeders before you start, (10mm X 1.5), and don't hesitate to replace them, they're cheap, and you don't want to twist one off.
I was told, (not sure why), to start bleeding at furthest wheel, (pass rear, then driver rear, pass front, then driver front).

You don't need to bleed the system if you just replace the fluid in the reservoir. If you do I would change it every week for 3 weeks to get more of the old crap out, but flushing the whole system would be better.

As I understand the system, (I could be wrong), the calipers are at the ends of the system, so I wouldn't think the fluid returns to the reservoir to mix with the new fluid. As the anti-lock system actuates, some fluid, (or pressure), is allowed to divert back to the reservoir, but with the system hydraulic, and the fluid non-compressable, minimal fluid volume needs to be relieved, (or diverted back to reservoir), to reduce hydraulic pressure.
IMO, flushing old fluid out bleeders, and allowing new fluid to replace it is the only way to go.

I can't say on these newer trucks, but on the 97 and older ones it still blended. I would put fresh fluid in the res. and with in a few days it would be just as dark as what I took out.

Bumpy... any more info on using a Tech 2 to bleed the system?

I bet heymccall could tell ya.