ATI brake

March 29, 2023, 01:36 PM

Ron Gusack

ATI brake

My trans builder installed an internal ATI brake (403080) in my T400. Now that I've got in the car, I decided to test the solenoid. I can't hear anything. I'm putting 13.3 volts to it while I'm under the car and I hear nothing. This isn't a wicked quick and the instructions say it only draws 1 amp. Does that mean it might be very quiet? My old external brake sounded like a small hammer smack.

This message has been edited. Last edited by: Ron Gusack,

March 29, 2023, 02:18 PM

markemark

With your meter set to ohms, place one probe to ground and the other to the wire terminal leading from TB button to solenoid. If you get a reading then you have a completed circuit to the solenoid. A reading over 20 ohms will be less than 1 amp.

If you place the meter leads in series between the TB button and solenoid you can determine the actual amount of current draw on the relay when energized. This value should coincide with ohms law for current using voltage divided by ohms = current.

With that small of a solenoid being used, it’d be very hard to hear submersed in fluid and attached to the valve body.

March 29, 2023, 06:53 PM

SCDIV1

The internal brake solenoid is very small and you’re not gonna hear it.

I had powerglides that had that same style brake in it.

The trans builder I used back then used an ATI valve body.

March 29, 2023, 07:56 PM

Fabman

If the car isn’t running you can still hear an internal solenoid click. It’s just muted being inside the trans.

March 29, 2023, 09:00 PM

ROLLIN'

Ron,
I had an ATI "internal" solenoid trans-brake in the 90's and it was inaudible also. Although it was in a PG, I've got to believe its very similar to what your experiencing. And yes the external solenoids are loud.

March 30, 2023, 10:39 AM

Ron Gusack

quote:
Originally posted by markemark:
With your meter set to ohms, place one probe to ground and the other to the wire terminal leading from TB button to solenoid. If you get a reading then you have a completed circuit to the solenoid. A reading over 20 ohms will be less than 1 amp.

If you place the meter leads in series between the TB button and solenoid you can determine the actual amount of current draw on the relay when energized. This value should coincide with ohms law for current using voltage divided by ohms = current.

With that small of a solenoid being used, it’d be very hard to hear submersed in fluid and attached to the valve body.

Thanks for your instruction Mark, I hadn't thought about reading ohms through the solenoid. According to my meter, I have 515 ohms through the solenoid. I struggle with reading digital meters. I think I have 515 and then I move the range to K and it reads 1.28. I would think it should read .5075 on the K scale. At least I know I have a completed circuit. Maybe I'll put my stethoscope on the case to see if I can hear anything. Thanks again Mark.

March 31, 2023, 08:47 AM

329L

If you have fluid in the pan, you most likely wont hear the solenoid click

April 04, 2023, 03:39 PM

FootbrakeJim

quote:
Originally posted by Ron Gusack:
According to my meter, I have 515 ohms through the solenoid. I struggle with reading digital meters. I think I have 515 and then I move the range to K and it reads 1.28.

Ron, I believe that is because you are measuring the Resistance through the solenoid coil. Even though you are using the Ohm scale, (Measure of Resistance), coils are not Resistors, they are Inductors, which are accurately measured by Inductance. Measuring Resistance of a coil serves to give you an indicator of continuity and a crude measurement of the presence of Inductance. Changing to a different resistance scale on a multimeter will push different levels of current, which will increase or decrease the Impedance of an Inductor. (Resistors convert electrical energy to heat, Inductors convert electrical energy into a magnetic field, which is what moves the plunger in your T-Brake solenoid). This concludes today's Physics lesson.

April 04, 2023, 09:21 PM

ferndaleflyer

I have used those internal solenoids from ATI ever since they had them and I can't hear them either. Of coarse I am old and deaf which could cause the silence also

April 05, 2023, 12:25 PM

Ron Gusack

quote:
Originally posted by FootbrakeJim:
quote:
Originally posted by Ron Gusack:
According to my meter, I have 515 ohms through the solenoid. I struggle with reading digital meters. I think I have 515 and then I move the range to K and it reads 1.28.

Ron, I believe that is because you are measuring the Resistance through the solenoid coil. Even though you are using the Ohm scale, (Measure of Resistance), coils are not Resistors, they are Inductors, which are accurately measured by Inductance. Measuring Resistance of a coil serves to give you an indicator of continuity and a crude measurement of the presence of Inductance. Changing to a different resistance scale on a multimeter will push different levels of current, which will increase or decrease the Impedance of an Inductor. (Resistors convert electrical energy to heat, Inductors convert electrical energy into a magnetic field, which is what moves the plunger in your T-Brake solenoid). This concludes today's Physics lesson.

Thanks for the lesson Jim, I greatly appreciate it.

April 05, 2023, 02:42 PM

SP 124X

Am I missing something here? Transmission is in the car why not just fire it up quick on jackstands and test it?

April 05, 2023, 08:38 PM

Ron Gusack

The car wasn't together enough to be able to start it and I meant to test it before putting the trans in.

April 06, 2023, 05:47 PM

BG7X77

quote:
Originally posted by FootbrakeJim:
quote:
Originally posted by Ron Gusack:
According to my meter, I have 515 ohms through the solenoid. I struggle with reading digital meters. I think I have 515 and then I move the range to K and it reads 1.28.

Ron, I believe that is because you are measuring the Resistance through the solenoid coil. Even though you are using the Ohm scale, (Measure of Resistance), coils are not Resistors, they are Inductors, which are accurately measured by Inductance. Measuring Resistance of a coil serves to give you an indicator of continuity and a crude measurement of the presence of Inductance. Changing to a different resistance scale on a multimeter will push different levels of current, which will increase or decrease the Impedance of an Inductor. (Resistors convert electrical energy to heat, Inductors convert electrical energy into a magnetic field, which is what moves the plunger in your T-Brake solenoid). This concludes today's Physics lesson.

Very Nice! Great explanation!

Someone who can actually respectfully answer a thread without acting like a total clown! Thank you sir!