Complete change of rake fluid (2005 AWD Astro)

[VanGeorge]

Great idea! I will get my wife out in the shop with me and try that tomorrow. I told a local 30 year Chevy dealer mechanic about my problem and he immediately said that both brake lines and calipers needed replacing because the lines probably have collapsed inside.

If I do the test and see the spray from one or both lines, I will replace them first and then test drive it again.

I don't intend to just swap parts until the problem goes away. I want to learn what the exact problem is so that I'll know if it happens again and also be able to help others who may run into the same situation.

Like I've always been told when flying my Gyrocopter, if you need to make changes, do them one at a time to see what effect it has on the flying of the machine, after all, your life is at great risk and if you make multiple changes, you have no idea of which one was the problem.
The van would be safer to make all the changes at once but I still want to gain some knowledge from this situation and be certain of the exact problem.
I'll let you guys know when the issue is solved and what it was.

[LiftedAWDAstro]

Since both brakes seem to be grabbing, make sure you pump them up between letting the bleeder loose. If both show pressure, the single rubber line going from body to axle is the culprit.

[VanGeorge]

Well, Here I am again with an update. Today I flushed the system with clean brake fluid. I got out all the fluid from the plastic reservoir with a small dipper. I then used a rag to clean the inside of the reservoir and got all the little gummed up corners, and crevices. It was as clean as I could get it without using brake fluid cleaner down inside it and I wasn't willing to do that.
I refilled the reservoir, put on the cap and went to the rear wheels and used the little bottle from Harbor freight that allows only one person to bleed and flush the lines.
The pressure unit that I purchased would not work because my reservoir does not have a screw on cap on top to use the adapter that comes in the pressure kit.
I jacked up corner, removed the wheel and connected the hose and bottle and pumped until there was no air in the lines. I closed the valve, removed the lines and moved to the next wheel. When I completed each wheel, I refilled the reservoir each time.
After all lines flushed, the pedal felt pretty good so I backed out and hit the road.......same problem but not as bad. I will get up to appx 30 mph and let off the pedal and you can feel the brakes slowing down the vehicle....Put her back in the garage to rethink and hope that someone will offer a real fix.
My reservoir is a two section, opaque in color and it slopes down toward the front of the vehicle. There is an opening between the front and rear reservoir to allow fluid to equalize somewhat, I can easily see the low fill point but cannot see the high level mark.
I put fluid in until it was at the front bottom edge of the reservoir. Measuring from the top opening I would guess it's appx 1/2 inch from the top of the reservoir when the cover is off.
Can anyone tell me exactly where the "Do not overfill" level line is supposed to be?
Another thing, on the rubber "Boot thing" under the plastic cap, the little round expanding circles that have been marked with a big plus are not extending into the reservoir, they are collapsed as I put that part on the inside of the lid and pop them into place.
Is this the correct reassemble procedure or should the little circle things be expanded to stick down into each reservoir, which would displace some of the fluid that is there now and possibly having too much fluid as one of you guys mentioned earlier.
I'd really like to have the Chevrolet Shop and service manual for this, there may have been enough info for me to not have had to reach out to you guys to begin with.

[Smiliesafari]

The top picture is correct. The bottom picture is correct. It sounds to me like it's time to replace the hoses.

[LiftedAWDAstro]

The problem is only 1 of 2 things…rubber lines or master cylinder. Do the tests I suggested and report back.

[crazyvanman]

Great idea! I will get my wife out in the shop with me and try that tomorrow. I told a local 30 year Chevy dealer mechanic about my problem and he immediately said that both brake lines and calipers needed replacing because the lines probably have collapsed inside.

If I do the test and see the spray from one or both lines, I will replace them first and then test drive it again.

I don't intend to just swap parts until the problem goes away. I want to learn what the exact problem is so that I'll know if it happens again and also be able to help others who may run into the same situation.

Like I've always been told when flying my Gyrocopter, if you need to make changes, do them one at a time to see what effect it has on the flying of the machine, after all, your life is at great risk and if you make multiple changes, you have no idea of which one was the problem.
The van would be safer to make all the changes at once but I still want to gain some knowledge from this situation and be certain of the exact problem.
I'll let you guys know when the issue is solved and what it was.

Had the problem with mine and had to do as your buddy said and replace the short hoses. Seems to have fixed the problem. Brake hasn't dragged since.

[Astrophysics]

Hi All,
Just re-read brake improvement and maintenance topics. My 2003 AWD/ 4WD has 135,000 miles.
I would like stringer brakes.
May look for new hoses and mabye new master cylinder.
I do have new hydra boost unit.
Original calipers and mid grade pads.

AP

[Herbie]

AP, I saw a noticeable improvement from switching to Hawk LTS pads, also.
(But yes, basic maintenance items are key also.)