is pad slapping bad?

[CarLuver]

i recently help a couple of my sons friends do brakes on their vehicles. one was a 2018 Volvo S90 T6 with 28k on the clock. its an expensive car but its leased and the parents are going through a divorce so the mom can not afford to take it to the dealer. dealer was close to $2k for brakes all around. i explained the options and they decided on a pad slap. i told them the possible pitfalls of a pad slap. it was all they could afford. So i pulled the pads and miked the calipers and they were good. for 28k there was no lip. greased the sliders other usual things . this was my first vehicle with electronic parking brake. it was a lot easier than i thought it would be.

put it all together and drove it. no shimmy , pulsing of anything. smooth as glass.

second one was a 2005 CRV. College student with no money. As with the previous one, i explained the options and issues . he also chose the pad slap. so i pulled the pads, miked the rotors etc and slapped it back together. the only issue with this one was one of the sliders pin was seized. cleaned and lubed . As with the other one when we drove it on the road there were no issues.

on my own vehicles i tend to replace or machine the rotors when doing a brake job. was told often that pad slapping was a bad thing . but this experience seems to contradict this thought. So why is pad slapping considered bad in the pro mech industry?

oh , my paranoid and careful self had them sign waivers on the brake jobs. i am only liable for a much as they paid me for the work.

 

[aquariuscsm]

Anytime I've done brakes I only replaced the pads.

My Z didn't need pads (rear) until about 119,000 miles.

My Accord still has the original pads, just hit 116,000 miles.

 

[Propflux01]

All the grooves are places that don't touch he pad. It will also wear the pads quicker. it works, just not as well and smooth as new or resurfaced rotors.

 

[A_User55555]

Id say its only bad if theres squeaks or shudder

 

[wings&wheels]

Growing up, that's how it was always done..... Now, I usually do everything incl. hardware, shims, sensors, etc. but 'brake jobs' are far between.

Is it optimal?? No. As long as the rotors are legal, not too badly worn, scored or rusted, you will be OK.

 

[The Critic]

It depends on the situation. Generally speaking, if you are using the exact-same brand/model friction material and the rotor surface is smooth, it is fine. I am also assuming that there was no vibration prior to the brake service.

Pad slaps usually work well for rear brakes, but almost never for fronts.

 

[GMBoy]

Usually if you are going to have issues with just a pad slap it won't show up until a few thousand miles as a brake shudder. If you do a proper brake pad bed in then you greatly reduce the chances of that happening. My estimate of all the brake jobs I do, that about 30-40% of pad slaps will end up with shudder and rotor replacements are needed. It is a good gamble anyhow as long as the rotors are good and you do a proper cleaning and lube job when slapping pads...and always use a top quality pad.

 

[c502cid]

If I do a pad slap I always use these on the rotor. Most of the time it's just fine.

 

[Wolf359]

It depends on the situation. Generally speaking, if you are using the exact-same brand/model friction material and the rotor surface is smooth, it is fine. I am also assuming that there was no vibration prior to the brake service.

Pad slaps usually work well for rear brakes, but almost never for fronts.

Funny that you mention that. I've done pad slaps on the rear on my Mercedes. The fronts were too chewed up for a pad slap. I do read in the forums that others have done it as long as the rotor was thick enough. Most of the time on other cars they're too thin so it doesn't work.

 

[Gyro Gearloose]

Pad slapping was the way I did it on all my cars prior to my 2004 model car. Since then it is the rotors that wear out, not the pads. Lately I've been throwing away about 1/3 of the brake pad's life because I get weary of the shaking at every stop from uneven rotors.

 

[Lubener]

Pad slaps often result in noisy brakes, less efficient brakes.. It's a partial job and why do that when it comes to your brakes.

 

[ka9mnx]

It sounds like you did the pad slap correctly. If everything looks and checks good and no prior pulsing pedal, I see no reason why not.

 

[supton]

Doesn’t bother me, as long as the rotors aren’t chewed up. But the rotors are usually heavily grooved by the time I need pads, so I do both.

I’ve had mixed results after 150-200k though, for some reason rear calipers like to be toast by then. The piston pushes in but in short order I get a dragging brake. There’s probably value in just replacing the calipers at the same time if after 150k, but then again, it’s not hard work, so maybe it’s worth doing twice in an attempt to save a buck.

On a 2018 though I wouldn’t think twice about a pad slap. On a lease I wouldn’t even think that much.

 

[Donald]

Just let the vehicle owners know that you can only do it once. Next time its rotors & pads.

 

[supton]

Just let the vehicle owners know that you can only do it once. Next time its rotors & pads.

Why only once? Why not until the rotors are in need of replacement?

I’m guessing people who track their cars must be doing “lots” of pad slaps?

 

[SHOZ]

I usually just do the pad swap. Rotors only after 150k or so.

The brembo rotors I have look smooth as new. Ford rotors always had the grooves.

Grooved rotors give you more surface area

 

[svtrit]

My son has a beater Camry that we did a pad slap on this past weekend. I told him I would replace the rotors as well, but being a starving college kid driving a beater, a pad slap would do for now. We properly bedded them in after installing.

Those pads and rotors will be paired together as they rust away in the junk yard 50k miles or so from now.

I’ve changed to doing rotors and pads on all my cars when doing a brake job. It’s not that expensive (when not a starving college kid) and is peace of mind.

 

[SHOZ]

My rear rotors have the ebrake shoes on the back side of them. Never had them off in 130k miles. I'm sure the shoes will need backed off to get the rotor off.

 

[64bawagon]

Pad slaps in the rust belt arent quite as common as other areas but if youre lucky enough to not have significant corrosion or surface issues and no pulsing then a pad slap is appropriate.

 

[blupupher]

I have not replaced rotors in the past 5-6 or so brake jobs I have done ('02 F150 front, '04 F150 front and rear, '10 Santa Fe front and rear, '12 Scion xB front and rear, '07 Saturn Vue front and rear).
I did do the rears on my F150, only because I got a package deal of EBC rotors and pads for just the price of the pads (pads sucked, rotors are fine).
My '04 Hyundai Elantra I had to do front rotors and pads together, they were just too thin and would end up with brake pulsing if not changed with pads regardless of what they looked like.