Questions about 01+ Booster/bmc assy. swap
#1
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Questions about 01+ Booster/bmc assy. swap
Hello everyone I have a 98 GS3 i am going to switch out the entire booster/bmc assy. for an 01+ unit I've already ordered , it should be here tomorrow but I have a couple questions before I proceed
Forgive me if these have been asked before
1.) I have searched the forums and read through all the recently bumped booster threads and I didn't see mention of whether or not everyone who switched out their entire assemblies also purchased a new brake booster gasket?
the service manual states that it's not a reusable part so am I right in assuming I'lll need to buy a new one?
no big, its super cheap from Sewell, part# 4478530040
2.)Will switching out the oil pressure sensors from the two assemblies insure that i will have a normally functioning unit ?(Good braking ,no lights on the dash, no codes being thrown, etc.)
Does this swap hold up well over time? any members who have done this to their car and put alot of miles on it afterwards please feel free to chime in.
I saw a thread a while ago where a member switched his 98-00 with a newer one and got lots of lights and codes but i believe he misinformed his mechanic and they did some sort of splicing of connectors to the harnesses to make them fit the 01+ sensor rather than actually swapping the sensors
Any input will be greatly appreciated
Thanks!
Forgive me if these have been asked before
1.) I have searched the forums and read through all the recently bumped booster threads and I didn't see mention of whether or not everyone who switched out their entire assemblies also purchased a new brake booster gasket?
the service manual states that it's not a reusable part so am I right in assuming I'lll need to buy a new one?
no big, its super cheap from Sewell, part# 4478530040
2.)Will switching out the oil pressure sensors from the two assemblies insure that i will have a normally functioning unit ?(Good braking ,no lights on the dash, no codes being thrown, etc.)
Does this swap hold up well over time? any members who have done this to their car and put alot of miles on it afterwards please feel free to chime in.
I saw a thread a while ago where a member switched his 98-00 with a newer one and got lots of lights and codes but i believe he misinformed his mechanic and they did some sort of splicing of connectors to the harnesses to make them fit the 01+ sensor rather than actually swapping the sensors
Any input will be greatly appreciated
Thanks!
Last edited by Jose98GS3; 03-19-13 at 02:27 AM.
#2
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Hows it going? I'm new to the club I've done the same swap! My rear brakes are too tight and grinding almost as if theres too much pressure! I can't figure out how to fix.
#3
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Hello everyone I have a 98 GS3 i am going to switch out the entire booster/bmc assy. for an 01+ unit I've already ordered , it should be here tomorrow but I have a couple questions before I proceed
Forgive me if these have been asked before
1.) I have searched the forums and read through all the recently bumped booster threads and I didn't see mention of whether or not everyone who switched out their entire assemblies also purchased a new brake booster gasket?
the service manual states that it's not a reusable part so am I right in assuming I'lll need to buy a new one?
no big, its super cheap from Sewell, part# 4478530040
2.)Will switching out the oil pressure sensors from the two assemblies insure that i will have a normally functioning unit ?(Good braking ,no lights on the dash, no codes being thrown, etc.)
Does this swap hold up well over time? any members who have done this to their car and put alot of miles on it afterwards please feel free to chime in.
I saw a thread a while ago where a member switched his 98-00 with a newer one and got lots of lights and codes but i believe he misinformed his mechanic and they did some sort of splicing of connectors to the harnesses to make them fit the 01+ sensor rather than actually swapping the sensors
Any input will be greatly appreciated
Thanks!
Forgive me if these have been asked before
1.) I have searched the forums and read through all the recently bumped booster threads and I didn't see mention of whether or not everyone who switched out their entire assemblies also purchased a new brake booster gasket?
the service manual states that it's not a reusable part so am I right in assuming I'lll need to buy a new one?
no big, its super cheap from Sewell, part# 4478530040
2.)Will switching out the oil pressure sensors from the two assemblies insure that i will have a normally functioning unit ?(Good braking ,no lights on the dash, no codes being thrown, etc.)
Does this swap hold up well over time? any members who have done this to their car and put alot of miles on it afterwards please feel free to chime in.
I saw a thread a while ago where a member switched his 98-00 with a newer one and got lots of lights and codes but i believe he misinformed his mechanic and they did some sort of splicing of connectors to the harnesses to make them fit the 01+ sensor rather than actually swapping the sensors
Any input will be greatly appreciated
Thanks!
2. yes. And it hold s up fine
The member who got the lights is an Idiot, he was told to search and even told to swap sensors. He didnt and cut wires, hence the lights.
#6
Lexus Test Driver
iTrader: (21)
What causes the MC to fail? Seems like this is pretty prevalent on the GS.
Poor maintenance (not cleaning brake fluid during sched. service)
roll of the dice
etc..
Looking to put on LS400's in the front and will get the fluid replaced. Didn't what a tech screwing up my MC when swapping out the fluid.
Poor maintenance (not cleaning brake fluid during sched. service)
roll of the dice
etc..
Looking to put on LS400's in the front and will get the fluid replaced. Didn't what a tech screwing up my MC when swapping out the fluid.
#7
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Do you have to swap the booster as well when you do the master cylinder ? That's the first in hearing of this. My bmc just died and I'm in the midst of swapping it for an 01.
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#10
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Search more! lol
But seriously you will have to change them both as they are one assembly
Edit: i am not a mechanic so dont take my word for gospel on this it may be that you can just replace the master cylinder however with the labor required and unless you're ABSOLUTELY 100% sure that its only the master cylinder which is faulty you are basically taking a gamble as to whether you will have to replace another part of the assembly later $$$$ also im not sure the 01+ master cylinder would be a direct fit into a pre 01 booster unit if that is the case in your situation
also a funny story i purchased a used 03 master cylinder/booster assy. which turned out to be damaged didnt find out till i installed it, had to pay to uninstall it then when they were bleeding my brakes they discovered both my rear calipers were totally shot and the front ones were in desperate need of servicing and had stuck pins and innapropriately installed pad clips they replaced the rears serviced the fronts and Voila! i didnt even need a darn booster in the first place! my soft pedal and brake squealing problems are gone! and ebay buyer protection is your friend
also DO NOT buy your unit from ahlautoparts out of oregon on ebay. they sent me a broken unit refused to take my return and now they are saying the part i had to get ebay to force them to take back is not the one they sent me
Ok so not such a funny story
But seriously you will have to change them both as they are one assembly
Edit: i am not a mechanic so dont take my word for gospel on this it may be that you can just replace the master cylinder however with the labor required and unless you're ABSOLUTELY 100% sure that its only the master cylinder which is faulty you are basically taking a gamble as to whether you will have to replace another part of the assembly later $$$$ also im not sure the 01+ master cylinder would be a direct fit into a pre 01 booster unit if that is the case in your situation
also a funny story i purchased a used 03 master cylinder/booster assy. which turned out to be damaged didnt find out till i installed it, had to pay to uninstall it then when they were bleeding my brakes they discovered both my rear calipers were totally shot and the front ones were in desperate need of servicing and had stuck pins and innapropriately installed pad clips they replaced the rears serviced the fronts and Voila! i didnt even need a darn booster in the first place! my soft pedal and brake squealing problems are gone! and ebay buyer protection is your friend
also DO NOT buy your unit from ahlautoparts out of oregon on ebay. they sent me a broken unit refused to take my return and now they are saying the part i had to get ebay to force them to take back is not the one they sent me
Ok so not such a funny story
Last edited by Jose98GS3; 05-01-13 at 01:03 PM.
#11
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What causes the MC to fail? Seems like this is pretty prevalent on the GS.
Poor maintenance (not cleaning brake fluid during sched. service)
roll of the dice
etc..
Looking to put on LS400's in the front and will get the fluid replaced. Didn't what a tech screwing up my MC when swapping out the fluid.
Poor maintenance (not cleaning brake fluid during sched. service)
roll of the dice
etc..
Looking to put on LS400's in the front and will get the fluid replaced. Didn't what a tech screwing up my MC when swapping out the fluid.
from my research i found that the two most common causes of failure were leaks or loss of pressure in the nitrogen canister and the motor failing(brushes eating the commutator i believe)
bad design and wear and tear basically in the pre 01 unit
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