Porter Cable 7424

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Nicki

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Hi All, Ever since I got the 7424 polisher, it seemed to operate in a random manner. It seems like it shuts off and on, when putting a load on it. Runs fine without touching the pad to the paint, but as soon as you do, it runs sporatically and HOT !
Its gotten worse, and cannot be used any longer. Is there a easy fix? Does anyone know what these symtoms are? I tried to contact the mfg., but they just want to send me to a repair shop.
I lost the operating instructions, so I digress to the experts.
Thanks in advance
Nicki
 
Hey, Thanks for the replys. The ext cord is a 12x20. I believe its a strong cord.
As to how old it is, I bought it is 2007, Used it once on a truck, went into storage for two years while overseas.
Nicki
 
What size Backing Plate and Foam Pads are you using?
 
I have been using the 3 1/2 pad holder and the 6" foam pads from a PBMA kit.
Nicki
 
Nappers said:
what size extension cord are you using?
Click to expand...

This is irrelevant. I use 100ft extension cords. It's all that we have at my folks' place.

Videos please? If it's turning on and off randomly I'd crack it open and check to see if the wires have come loose from the switch. Also check the brush. If it is nothing obvious like that, you will need to send it off.

I can have pictures if you want.
 
You are so right. If had saved the instructions, I would pull it apart. Do think the armature is dirty? Bad Brushes? Anybody with an exploded view?
Thx
Nicki
 
I would think the carbon brushes. If im not mistaken it uses the same kind of motor we use at work on our machines. Should be able to just unscrew and check them.
 
That is a very small backing plate for a 6" pad.
 
Using too small of a backing plate will just cause ALOT of wobble and hurt your forearm pretty good... It shouldn't be turning on and off like that though.


My guess is that you used that pad/backing plate combo and it shook so violently that it pulled a wire going to either the chassis ground or to the live wire and it's making a bad connection due to the vibrations.
 
Are you sure the poly washer is on the stud under the backing plate? What I have seen typicaly is that it boggs down really hard and sometimes won't turn if that is missing. Just a thought.
 
I will try to pull it apart to check for bad brushes, as for the pads and backing plate, they all came as a kit from PBMA.
Thanks, Nicki
 
zinc02gt said:
This is irrelevant. I use 100ft extension cords. It's all that we have at my folks' place.
Click to expand...

actually it is relevant on any power tool used with an extension cord.

If it is a tiny (cheapo) extension cord then it could cause issues (though usually with the cord getting too hot or the device not getting enough power).

Im referring to the guage thickness (how big around it is, not how long it is)..the longer the cord, the thicker it should be to conduct electricity better.


The dollar store extension cords would not be a good choice to be used with the 7424, lol.
 
Nicki said:
I have been using the 3 1/2 pad holder and the 6" foam pads from a PBMA kit.
Nicki
Click to expand...

Nicki,

The problem is either really simple, or the tool is somehow broke.

First lets address the pad size, this is what a 3.5" backing plate looks like on a Porter Cable 7424XP. The 7424XP is the newest version of the Porter Cable Dual Action Polisher but your 7224 or 7336 would be approximately the same dimensions.

3_5DualActionFlexibleBackingPlate01.jpg


3_5DualActionFlexibleBackingPlate02.jpg


3_5DualActionFlexibleBackingPlate03.jpg


We do sell kits that come with the 3.5" backing plate but they are intended to be used with 4" pads, not anything larger.

This is just an aside because this wouldn't have anything to do with the motor stopping when the switch is still turned on.

It's fairly common for the the cord to become damaged where it enters the back of the tool and to have the electrical connection partly broken.

Usually if this has happened you should be able to turn the polisher on and wiggle the cord where it exits the back of the body and cause the tool to quit running, it's pretty simple experiment to do.


The heat issue is kind of subjective, the body of the tool can get warm but I don't know I've ever used one to the point where it was too uncomfortable to hold in my hand.

Any vibration noises could be something internal or as was pointed out a loose backing plate due to a spacer washer missing.

Can you check any of these things and see if any apply?


:)
 
Ahh, my mistake on the backing pad size. I eyeballed it. sorry. It's four and three quarter.
I tried the cable end by moving it back and forth, no difference.
Trying the polisher without a load, same problems.
If anyone knows how to get the plastic cap off, I could check the brushes and clean the armature. Anyone ?
Thanks in advance,
Nicki
 
Is returning it to the place you purchased it an option?

Here's two other options, some ACE Hardware stores are also certified Porter Cable service centers, check with your local ACE Hardware store and see if they are a certified Porter Cable service center.

Click the link below, it will take you to an online form that will help you locate an authorized Porter Cable repair center, take your tool to them and have them inspect and make any needed repairs.

Delta/Porter Cable Service and Support


:)
 
I bought it from YOU aka PBMA. Would you like it returned?
It's only got 4 or 5 hours on it.
Nicki
 
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