How to check front brakes

Have some front brake issues which I need to check out for seized piston, etc. etc. Question is exactly how do you push the pistons back or pull the brakes back from the disc to then test how they close? Pulled the wheels last night and my pads rest on the disks slightly and I didn't see way to retract them. Is this normal or does it indicate another problem like problem with flexible fluid lines (they look O.K. on outside but can't tell when last replaced)? If this is in a book that I should have read, just aim me. Thanks.

You do have the Haynes manual, right??

i'm probably wrong, but it's how i do it...<>open master cylinder cap and remove. <> use old brake pad or peice of wood reverse on cylinder <> get C-clap and slowly tighten. <> if cylinder is not frozen, it should move back just dandy. this is how i replace pads.

make sure the master cylinder cap is off, though...i forgot once (old age? laugh!) and ruined the caliper.

since your there...replace all the hoses...about what, $20 bucks? take off the hoses, remove calipers...install new pads...bleed system....see what happens. $20bucks and a couple hours. if the calipers are bad, you'll have to do it all over again, though, once you put rebuilt ones on. i ended up doing this drill 5 times to the same car. but that's because i started with bits and peices and decided to do it all in one swoop before planting my butt in the car.

On Land Rover calipers, I open the bleed screw when I push back the piston. That way old nasty brake fuid does not go back up the pipe. I then, re-bleed adding new fluid until I get new fluid at the caliper. I need to do this soon to my brakes, let me know how it works out.

In addition to taking the cap off of the MC, if you have been keeping it topped off, you need to remove about an inch of fluid to allow room for the fluid you displace when you push the caliper cylinders apart. I just did brakes on my 79, and was surprised at how much fluid moves back up to the MC. No big deal for my as I need to paint my engine bay anyway, but if you got good paint by the MC, you won't for long, if you overflow the MC

Ed

Gary,
Yup, got Haynes & Bentley. Just wanted people's tricks and little things they don't tell you in the manual. I still consider myself a novice mechanic and not very intuitive yet even though I have done a bunch of stuff on this car, so need all the help I can get.

Phil, John, Ed,
Thanks for the tips.

Will do it tonight and tomorrow night and let you all know how it turns out. Sorry, forgot my Southern roots...that's "ya'll".

JTB

John,
I usually just use a big screwdriver to pry against the rotor and push the piston in. Just be careful to not gouge the rotor (or slip off and bang up your hand -- BTDT!)

HTH!

Geez Rob... 'lil extreme

Don't pry directly on the pad material it will chip and
you'll gouge the rotor. bad advice... poor practice.

Firstly understand that heat plays a critical role here.

What works well at room temp will fail at hi-temp.

You should be able to press fully upon the break
the pad/rotor should lock the wheel from rotating.

Release break pedal and the rotor should be free to
spin directly. at worst within a second or so. If you
do not have this marginal of movement you need
to address caliper/MC/hose issues.

Many hoses collapse internally and in effect become
one way valves at temp. Caliper actuates fine but will
not retract until the caliper cools.

You do not explain your "issues" only that you do not "see"
the caliper retract. Really souldn't see it retract. But should
be able to move the wheel / or rotor within the pads...
(gotta be accurate and politically correct)

Rest of the posts are excellent. If you work on a car with ABS
absolutely open the bleeder to run in the caliper piston. On our
old systems it's not needed but still a good idea if you don't mind
bleeding them out (ought to anyway). Before you grab that c-clamp
and crank down the piston clean the outside of it well so the dust
seal and inner rings arn't damaged when seating the piston.

If the symptom is seizeure during operation don't skimp and rebuild the
caliper and replace the hoses. Not a break job comes into the shop
without the flex lines being replaced if 75k is on the clock. (american
and import cars) Standard practice here with experience being the
teacher.

Oh and before you ask Don't beat off the rear drum with a hammer either...

.0025$ FWIW

Actually, if you open the bleed screw as you retract the piston and then close it back before you release the piston, you shouldn't need to bleed the system since you didn't introduce any air into the line. But......anytime I'm there, I'll bleed it anyway. It can't hurt....might help....quick and easy to do....coulda been air in there already....

HowY,
Thanks for the great details. Didn't want to drag every one in on the "issues" as I previously posted about it separately. Basically, car is pulling to the right after first couple instances of applying the brakes each time I go out. Car is 69B. Pull is a steady pull. No surging or locking. The hub without the wheel on it rotates but not freely.

That is good!! It will really help!! Yup!! Tips are always good!! I wasn't being rude, just asking, because that is a first!!

John take a huge pair of water pump pliers and squeeze the brake tab and the back of the caliper together and the brake wil retract and then you can take them out to view the caliper piston.....if the piston is seized you would have smelled it as you drove and if you feel the wheel it would have been super hot. But if you have a seized caliper replace in pairs. and when you button it all back together before you roll, pump the brakes a few times to get a pedal...nothing is more embarassing that to back out and hit the brake and nothing......happy tails

this thread is just what I need!

are calliper mounting bolts usally stuck on pretty good? I bent back the tabs as best I could (used a 'drift') and a BFW to no avail, albeit I am quite frail! very little "experience" hanging around on my body to help me bust open some bolts

I've never had any problems with them

I'm the super weak!

I need a good 6-point socket for it, I got a 12pt in their size, but I already skipped out of that one once on one bolt, so I gave up, my end wrenches are too small

John,
I just did that last week, and yes, the bolts holding the calipers were a bit$h. The DPO had rounded one pretty well, but once I got a six point impact socket at the pawn shop, and a breaker bar, it got persuaded to come out. The fact that I shot it with Aerokraoil (sp) and let it soak while I drove to town for the socket, probably help also.

Ed

I got some Really Good @!#$ (RGS) penatrating oil at work, I'll borrow the can for a night maybe that'll help

Use a 5/8" 6 point, 1/2" drive socket with a breaker bar, and give it a good whack out near the end with a soft, heavy mallet, it'll come loose. Very often, the impact will loosen things much better than simple torsion.
As to retracting the calipers, I also use a long screwdriver. Caveat here, though, I only do that when I am going to replace the pads, anyway.

Good stuff, guys. Like that "water pump pliers" approach, Jerry. I assume that means behemoth angled/offset pliers. Have a huge pair with red plastic sleeves on the handle.s Only get to use them a couple times a year when I need to intimidate something big.

JTB

I use the big welding clamp vise grips instead of pipe pliers as you get more pressure (good for the stuck ones). Theres not much that won't wove with them