J55 clarification
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Instructor
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From: Las VEgas NV
J55 clarification
I thought J55 was better calipers and rotors, but after reading the FSM today it looks like only bigger (13) rotors and the same calipers as standard. Can someone confirm this.
Le Mans Master
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From: Houston Texas
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Instructor
Joined: Sep 2003
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From: Las VEgas NV
I thought they had to be different. Just going through my new copy of the FSM (1994), and was actually a little disappointed in some of the content. I am sure it is a great book to have, but did not show a different caliper for J55, although it did reference the larger rotor, could not find what thermostat I have, and no reference to the oxygen sensors. Am I mission something? Yes I do have both books.
Team Owner
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I thought they had to be different. Just going through my new copy of the FSM (1994), and was actually a little disappointed in some of the content. I am sure it is a great book to have, but did not show a different caliper for J55, although it did reference the larger rotor, could not find what thermostat I have, and no reference to the oxygen sensors. Am I mission something? Yes I do have both books.
I believe you found the reference to the rotor difference in both brake systems as well as dimensional specifications of both rotors for evaluation of condition. The diagnostics of the brake hydraulics is the same regardless of the caliper so there's no need to address the differences, the pads are the same for both also. A measuring device is all that's required to confirm the brake option of your car. Rotor diameter and/or thickness.
Last edited by WVZR-1; Oct 22, 2013 at 01:23 PM.
Drifting
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From: New Jersey
Rhino - just FYI, if you have your owners manual, it will state the thermostat temp. which is 180 degrees along with a lot of other interesting information. Don't forget that it is an LT1 specific thermostat - a regular thermostat won't work.
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Instructor
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From: Las VEgas NV
Thanks. I do have an owners manual, but it is in Vegas and I am in Saudi Arabia
Thread Starter
Instructor
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From: Las VEgas NV
It is NOT a "parts book" but a "service tool" - There's I'm sure diagnostics in there for anything that you could likely come across.
I believe you found the reference to the rotor difference in both brake systems as well as dimensional specifications of both rotors for evaluation of condition. The diagnostics of the brake hydraulics is the same regardless of the caliper so there's no need to address the differences, the pads are the same for both also. A measuring device is all that's required to confirm the brake option of your car. Rotor diameter and/or thickness.
I believe you found the reference to the rotor difference in both brake systems as well as dimensional specifications of both rotors for evaluation of condition. The diagnostics of the brake hydraulics is the same regardless of the caliper so there's no need to address the differences, the pads are the same for both also. A measuring device is all that's required to confirm the brake option of your car. Rotor diameter and/or thickness.
Don't get me wrong, love my vette, just a little disappointed in first glacé through the VERY expensive FSM looking for O2 sensors and thermostats. Am I am sure that when I need it it will be worth it's weight in gold.
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From: Lacey WA RVN 68-69
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So where does it show how to replace the oxygen sensors. I can't even find them in the index. Looked up oxygen, heated oxygen, O2, lean, etc. just an example from the FSM. And yes I know it not a parts manual but to not even list the temp on the thermostat seems a bit weird and to list the part # for cooling System sealer pellets (GM 3634621 and Alumimun radiator repair kit GM 1052617, but no specifics on the thermostat. But then again, same group that put the water pump on top of the optispark.
Don't get me wrong, love my vette, just a little disappointed in first glacé through the VERY expensive FSM looking for O2 sensors and thermostats. Am I am sure that when I need it it will be worth it's weight in gold.
Don't get me wrong, love my vette, just a little disappointed in first glacé through the VERY expensive FSM looking for O2 sensors and thermostats. Am I am sure that when I need it it will be worth it's weight in gold.
As far as part numbers, the techs don't worry about that because the parts guys deal with that. If a tech needs a thermostat for a '94, the parts guy goes to the computer (or the parts book) and finds the part number, goes to the shelf, grabs one and hands it to the tech. There is no selection by temp for a factory 'stat.
For the O2 sensor, they will be located on the exhaust pipe in front of the catalytic converters. They simply screw into a threaded bung and a single wire is attached to the sensor pigtail.
The later C4's will have 2 and possibly 4 sensors depending on the year. The second pair will be after the cats.
We can thank the engineers for component locations The SBC water pump has been in the same spot since 1955. The Opti is supposed to be an improvement over the standard distributor and it may very well have not been the best idea.
Burning Brakes
Joined: Oct 2002
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From: Denver CO
I know this isn't really what your post is about, but if replacing the after cat O2 sensors, than it is simple enough. Just put the car on ramps or jack stands and unplug the connectors and unscrew the sensors from their location on the exhaust pipes (after the cats). Pre cat sensors are on the pipes coming from the manifolds before the cats. Same thing, just unplug them and unscrew them from the bungs on the pipes. Install is reverse.
Burning Brakes
Joined: Feb 2002
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From: South Riding VA
So where does it show how to replace the oxygen sensors. I can't even find them in the index. Looked up oxygen, heated oxygen, O2, lean, etc. just an example from the FSM. And yes I know it not a parts manual but to not even list the temp on the thermostat seems a bit weird and to list the part # for cooling System sealer pellets (GM 3634621 and Alumimun radiator repair kit GM 1052617, but no specifics on the thermostat. But then again, same group that put the water pump on top of the optispark.
Don't get me wrong, love my vette, just a little disappointed in first glacé through the VERY expensive FSM looking for O2 sensors and thermostats. Am I am sure that when I need it it will be worth it's weight in gold.
Don't get me wrong, love my vette, just a little disappointed in first glacé through the VERY expensive FSM looking for O2 sensors and thermostats. Am I am sure that when I need it it will be worth it's weight in gold.
Another good resource (although it's a subscriptioin service) is All Data. It's like an online FSM and it's somewhat easier to search.
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I have an old white manual # ST-364-94PSID for 94 has location for 02 on page 6E3-A-5, description on 6E3-C1-5, location with pic. 8A-201-17.
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From: Anaheim CA
You have to put this in perspective. When the J55 brakes were introduced in the late '80s the stock brakes were 12" discs with single piston calipers.
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Instructor
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From: Las VEgas NV
The real reason for the O2 search was to see it the 94 had 2 or 3. I still think 3, even though the FSM says 2.
Last edited by rhinoevans; Oct 26, 2013 at 09:26 AM.
Team Owner
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Where in the FSM do you see only 2 O2 for the LT1 engine? You're not quite acquainted yet - you will become more familiar. The FSM has images with the 3 locations and also an electrical schematic also. Book 2 is where the information is located.
Burning Brakes
Joined: Feb 2002
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From: South Riding VA
correct, it does have 3: 2 pre cat, one post cat. If you are replacing them, the two pre cat sensors provide the data for mixture etc. The one post cat is only there to check cat operation.