Replacing Caliper 99 Silverado

Having ABS problem. After removing wheel to get to wheel sensor I notice the Caliper is dragging. So I plan the whole thing Caliper,pads, rotors Wheelbearing/Hubs. Now my question is These are original and there is a ton of rust over EVERYTHING. I can't tell if the bolts are Torqs or Allen heads. I imagine I may have to replace Brake line coming out of caliper because of Rust. I have been spraying pb blaster and doing some light tapping with a hammer hoping to start loosing up rust/bolts. Have not attempted to remove.
Any suggestions on proceeding? Don't know if there is something else I should use in hope of freeing up rust. :runaround:

Having ABS problem. After removing wheel to get to wheel sensor I notice the Caliper is dragging. So I plan the whole thing Caliper,pads, rotors Wheelbearing/Hubs. Now my question is These are original and there is a ton of rust over EVERYTHING. I can't tell if the bolts are Torqs or Allen heads. I imagine I may have to replace Brake line coming out of caliper because of Rust. I have been spraying pb blaster and doing some light tapping with a hammer hoping to start loosing up rust/bolts. Have not attempted to remove.
Any suggestions on proceeding? Don't know if there is something else I should use in hope of freeing up rust. :runaround:


your question / issue is confusing.
to remove the wheel sensor in the front hub you must remove the front rotors. do you have these removed ? sensor held in by allen screw.

the caliper pins did you remove them ? need torx bit, with these removed and the caliper brake hose removed see if the caliper piston moves freely.

with the abs sensor removed does the grease look like rusty color if so the hub is bad . if the grease is bluish color its good.

most likely the ABS sensor mounting suface needs filing , to smooth out the rust then install and check for 380 mv ac minimum with your spining the wheel hub.

make sure you don't allow brake fluid to drain out or the abs pump will get air in it !

I can see how my question is confusing. I am trying to get to the wheel hub to prove if it is sensor or to see if the hub bearing is bad. At this point I am using anything I can to remove rust so I can remove bolts or pins to remove the Caliper so I can get to the sensor / hub. I just have never seen so much rust built up where I cant determine what tool I need to remove the bolts/pins.

Since the caliper is dragging I am going to replace it. I will replace both front calipers. The next challenge I see there is all the rust on the brake line going into caliper. If I have to replace the brake line coming out of the caliper I do not know how hard it is to bleed the brakes with abs.

Before replacing caliper make sure the rubber brake line is not holding pressure on caliper.
Open bleeder on caliper and see if drag goes away.
If so replace the rubber brake line.

I can see how my question is confusing. I am trying to get to the wheel hub to prove if it is sensor or to see if the hub bearing is bad. At this point I am using anything I can to remove rust so I can remove bolts or pins to remove the Caliper so I can get to the sensor / hub. I just have never seen so much rust built up where I cant determine what tool I need to remove the bolts/pins.

Since the caliper is dragging I am going to replace it. I will replace both front calipers. The next challenge I see there is all the rust on the brake line going into caliper. If I have to replace the brake line coming out of the caliper I do not know how hard it is to bleed the brakes with abs.

using water soap and a good wire brush you can remove this rust quite effectively. then when dry spry the parts to be removed with penitrating oil. not wd-40 . allow a few hours to work in and repeat application..

the caliper torx bolts/PINS can be impossible to remove with low quality torx. need a good torx bit with a flat bottom to set into the shallow hole .if thiis is impossile to remove then just unbolt the caliper from the lower control arm.


the rotor should slide off .if not spray this down with the oil and give it some light taps using a piece of wood on the rotor surface

clean up the area where the sensor is mounted using the water soap and wire brush ..I have many sized brushes a small narrow one works good here . un screw the allen stud on the sensor spray with penitrant and gently rotate cw/ccw as you pull out.

must also have a C clamp for the caliper piston to be pushed back ..


when replacing any brake lines you must not allow the brake fluid in the system to leak out with line removal. a little leaking is ok for a short time . so when cutting in the new line plug the system so you do not drain the brake system down.

the flex line to the caliper should be good . the metal lines are a problem especially on the driver side

What size Torx does it take to remove the caliper? I had mine off today but don't have the correct size in any of my kits & don't know what to ask for at parts store.

What size Torx does it take to remove the caliper? I had mine off today but don't have the correct size in any of my kits & don't know what to ask for at parts store.

I got the torx 55 from sears automotive section NOT the regular tool section. this must have a flat bottom so it will set deep into the head of the caliper pin stud. my other t-55 do not work in this application . I broke these other t-55 'S from autozone/advance auto [cheap chinese crap ]....

What size Torx does it take to remove the caliper? I had mine off today but don't have the correct size in any of my kits & don't know what to ask for at parts store.

so what's your problem ? same as the other forum member ?

I will try opening the bleeder first. Do I just open it and shut it or or do I need to have someone apply pressure on the brakes?

j Cat I see what you mean about the metal brake lines. I have replaced brake lines on pre ABS cars. Can a average person replace these or do I need to take it to a shop. I have made brake lines in the past. Not sure what I would get into with ABS pump or bleeding the system.

j Cat I see what you mean about the metal brake lines. I have replaced brake lines on pre ABS cars. Can a average person replace these or do I need to take it to a shop. I have made brake lines in the past. Not sure what I would get into with ABS pump or bleeding the system.

with abs as long as you do not allow much fluid to come out your ok . lets say you mess up and air gets into the ABS then you will have to bring the vehicle to a repair shop with the proper beeding equiptment..

what this does is activate the abs pump with the bleeding screw open at the calipers.

I have replaced most of these lines, I have not had problems.

make sure the line going to the rear next to the fuel tank is good[hard to inspect] this one blows often and you will not stop..

buy 25 ft roll of tubing and use the double flare kit. not hard .

so what's your problem ? same as the other forum member ?

No, I was just going to replace the pads & realized I didn't have the correct wrench. I figured it would still be the large Allenhead.
I came here to post the question & saw this thread so figured I'd add to it rather than start a new one.
I'll go to Napa tomorrow & hopefully find a good one.
Thanks for the info.

I will try opening the bleeder first. Do I just open it and shut it or or do I need to have someone apply pressure on the brakes?

when pushing the piston back you open the bleed screw and using a C clamp push the piston back. then close the bleed screw.


when bleeding fill the res. container then close cover. have assistant slowly pump brake pedal then with max pressure on pedal you slowly open the screw until you get good flow. then close screw .repeat all this until fluid is clear and no bubbles..rt rear first then lft front last.

work on rear or front one at a time . dont do both front and rear at one time when making repairs to lines/fluid.