Loose pressure in my brakes 1998 plymouth grand voyager i have no fluid loss the master be changed whole system bleed . the weired part in it seems like it keeps getting air in. after bleeding the b

The master cylinder doesn't have a bleeding screw. Bleeding screws are located on each front caliper and the rear drum brakes. You'll need an assistant to press the brake pedal down on signal as you open the bleed screw slightly and close it back before they allow the pedal to return to normal position each time, until you've purged it through with new clean fluid. Fill up the master cyclinder frequently as you do this to assure it doesn't run dry. (If it does the master cylinder may be toasted.) Remember bleeding these types of cars is different than many others as it has dual lines, one for each side of the car. the bleed order is: LR, RF, RR, LF to get all the air out of the lines properly. Brake should be replaced every two years in humid or wet climates as brake fluid is hygroscopic... attaches to water vapor and stays in the braking system.

open bleeder nut have someone step on brake peddle, depress, then air and fluid comes out, keep pedel down, tighten nut. do it until only fluid comes out. 3 times should be enough. Make sure to put clean brake fluid back into brake master. Keep full if you suck in air you have to start all over.

Never brake fluid and nothing else goes in brake master cylinder.

Put power steering fluid or automatic transmission fluid (dextron)

You never replace only one caliper

You do both sides

Bleeders are mounted to top of caliper

Have a helper in drivers seat to slowly
press brake pedal as you open & close
bleeders

Start at back & do all 4 corners

The master takes care of it's self

Fixed--- I don't think so !!

3 Mechanics-that is sad

How about the power brake booster?
Was that checked & the vacuum check valve okey?

You wouldn't be happy if that solved the issue & you
got the valve off the wall on a trip thru the parts store
& installed yourself

What about ABS Issues?

What happens if you command the valves open
with a scan tool,bleed system & test drive with scanner
and valves still open or disconnect the motor to it & drive
around a few days.

I remember a load leveler valve under the back on
the drivers side on some caravans?

The fluid has to go somewhere,if not back into the reservoir,
then the abs unit maybe.

Better check the not leaking part yourself, unless you don't
loose any fluid

You bleed them there okey for 3 days,why,that is the key,
then what?

Regardless of what vehicle you have, brake fluid should be changed about every two years because it will and does absorb moisture from the atmosphere. Water or moisture in your brake fluid will turn to steam under pressure (heat) as in repeated braking, braking going downhill, etc. You can't compress the steam as well as you can brake fluid, so replace it and avoid potential brake failure. It's an easy enough job to do yourself with a brake fluid replacement kit. There are plenty of YouTube videos on how to do it. Be sure and get a Hanes, or other owner's manual, or check with your auto parts store to find out the ORDER in which you bleed each brake. Most cars start with the front lines, then work around, but check to be sure what the order is for your particular make. If it hasn't been changed in awhile it will be dark. Keep adding and bleeding until the fluid runs clear. Here's a good YouTube video on how to bleed your brakes: https://www.youtube.com/watch?v=EkmKGptc4rM

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/becky_74db42375768192e

air must be entering the system somewhere, check all wheel cylnders for leaks, and check the master cylnder for leaks( some cars's master cylnders leak at the firewall and fluid runs down inside the car under the carpet)

Find the master cylinder. It has a yellow cap on it and should be located in the engine compartment, in the corner right in front of the driver and it's attached to the brake booster.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/michael_2496c4f07ad24453

You may have to bleed the entire brake system. Air in the line can cause this problem. They may have bleeding instructions on the master cylinder reservoir(the 1993 model does). With some tubing ,some brake fluid, a pan or jar, a wrench ,and a helpers foot you can do this bleed this yourself .Just be careful not to put in more air than you take out.

transmission fluid
cooling system
power steering
brake fluid