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I'm thinking of switching to a LS1 Booster and MC. I tried to but haven't come any REAL answer as to what i need to change. Also hear problems with "spongy" feel. What can i do to fix this now? FWIW I'm doing this cause the LS1 booster sits closer to the firewall and I'm trying to make more room in the engine bay. Also would a LT1 booster work as well? I have a complete LT1 Booster and MC. Thanks for the help.
How much closer is the LS booster really??
I can't imagin its more than a 1/2".. Maybe it is
I hav seen a bunch of them swapped but I really don't know if its worth it other than saying you did it.
You can see the LT1/LS1 are smaller in length. The LT1 and LS1 master are the same only thing that is different is the reservoirs and one fitting size on one line... the Ls1 is a direct bolt in the LT1 you need a adapter to correct one of the line sizes...
Last edited by FueledSoul; Jun 27, 2012 at 12:21 AM.
Wow awesome. I'm assuming LS1 weighs slightly less perhaps? Probably so minimal it's not worth weighing. This looks like it takes up less space under the hood which is always a good thing!
Wow awesome. I'm assuming LS1 weighs slightly less perhaps? Probably so minimal it's not worth weighing. This looks like it takes up less space under the hood which is always a good thing!
Where talking ounces if even pounds... the ls1 master is a tad lighter and the boosters are about the same, there boosters... so yeah not even worth weighing lol... the 4thgen stuff takes up less space and also looks nicer especially the 4thgen booster, its much smoother.
Definately interested in this but i may go hydroboost to get ultimate performance from my big cam. Very little vacuum
I assume performance is similar to thirdgen booster even tho the bore size in the master is different?
I was looking into hydroboost as well since i will eventually swap in a different motor and a cam that is borderline with the amount of vacuum needed for the booster... you shouldn't have a problem running a radical cam if you use a vacuum reservoir or a electric vacuum pump... but hydroboost is the way to go, your brakes feel and operate the same regardless of engine speed...
3rdgen and 4thgen brake booster are both dual diaphragm uints so in the nut shell performance wise they are the same but the master is a different story, i pulled this off of another site
"Hydraulic principals are fairly simple and function on pressure which is force per unit of area, so the smaller the bore master cylinder, the higher the pressure output for a given input force. The inverse is true as well, so the larger the bore master cylinder, the lower the pressure output for a given input force. When evaluating master cylinders for a given application, you're choosing a balance between pressure and volume because the two are inversely related. As you decrease the MC bore size, you increase the pressure output but decrease the volume output proportionally. Additionally, pedal travel increases as well when you decrease the MC bore size since the volume requirements haven't changed, so you need to design for a certain volume requirement with your pedal ratio and packaging constraints since pedal travel and MC stroke length can both be limiting factors if you go too small on the MC bore size."
So I finished polishing my fourth gen master cylinder and have my fourth gen brake booster, is this going to be a straight forward swap? No extra cutting or brackets to make? No holes to drill, enlarge or elongate or slot?
New polished master cylinder and polished bracket for clutch fluid mount up fine to the thirdgen brake booster. I'll be "upgrading" to the fourth gen if it's exactly like replacing the original.
FueledSoul, in post 11 you said you used an LT1 master and LS booster. why did you use this combo vs a LS/LS? the LT reqs an adapter to correct a line size.
You would be right with the lt1 master.Read it again im running a lt1 booster and ls1 master
Two of the auto parts stores that I have checked have the same part number for all fourth gen power brake boosters. Is there a difference in LT vs LS brake booster? If so what part numbers or where did you get yours?
Fwiw.
On my 00 camaro ss i daily drove a 500rw 11:1 245/248 .620/.630 110 cam
And had zero braking issues regarding vacuum. Or braking distance,pedal feel,etc.
Does it affect stock 3rd gens braking systems with big cams.
Im gonna be upgrading my to 00 booster anyway.
I ordered the fourthgen brake booster and am puzzled as it "appears" to be the exact same dimensions lengthwise. I measured the old one front to back on the car and it is the same as the fourthgen????
So now I am really wanting to know where FueledSoul got that booster, Junk yard, dealer part, National auto parts chain etc.?
The real question is it worth it I have a ls1 master and I'm doing a ls1 brake swap. Do u feel a difference
Not sure if there would be a difference. I am changing mine out now. I have a manual transmission so it is very tedious work removing the four bolts on the driver's side interior firewall. Maybe an hour just to remove four bolts....
I want to just switch the master cylinder with one from a 4th gen. I understand I have to tweak the lines a little but is there anything else I need to do?
I want to just switch the master cylinder with one from a 4th gen. I understand I have to tweak the lines a little but is there anything else I need to do?
No, bolts right up. But I would change the booster at the same time since you are already four bolts away from replacing a 22+ year old piece.
Ido have the master cylinder and booster from the fourth gen. Is there a link to a thread that explains the step by step procedure? Or is it simply just changing them out?
It's pretty straightforward, unbolt the old and bolt in the new. If you need more explaining as to how to replace a master and booster you'll need to purchase a Haynes or Chilton manual.
Any time you disconnect the master cylinder from the lines you should bench bleed it. It only takes a few drops of air to displace fluid to cause you to bench bleed.
I'm replacing the brake power booster in my 1988 IROC with one from a '98 Camaro.
It's a right hand drive car and I need to move the master cylinder back for clearance from the strut mount.
Found the 4th gen booster is about 2cm slimmer. The studs into the master cylinder are exactly the same size, although the studs thru the firewall are a size smaller.
Here's the brake switch that i had to set back to correct the rod length issue... Just jam nutted it in place
For those that swapped in an LS1 bootser, how much did it raise the brake pedal? Just a rough estimate, the rod looks to be about 3/16" longer (the part that protrudes inside thru the firewall). I would imagine 3/16" at the rod would equal at least 1/2" or more at the pedal.
Has anyone doing the LS1 Booster and Master swap had an issue with hood clearance? I have everything mocked up on my car right now and I am fairly certain after everything is torqued down the master cylinder is going to be sitting up higher than the hood.
Original Brakes and motor
Ls1 Brake Booster, Master Cylinder, 3rd gen prop valve
Has anyone doing the LS1 Booster and Master swap had an issue with hood clearance? I have everything mocked up on my car right now and I am fairly certain after everything is torqued down the master cylinder is going to be sitting up higher than the hood.
Original Brakes and motor
Ls1 Brake Booster, Master Cylinder, 3rd gen prop valve
Are you sure it's mounted correctly? It looks like it's sitting no at an angle.
I dont know how one would mount this incorrectly. It has 4 studs that slide right into the firewall. It isnt fully torqued down on the 4 bolts in the back yet, but even when i push it down as far as it goes it seems high. I am gonna play with it tonight and see if i can figure out the issue. I looks to me as if the LS1 booster has an angled mount on it compared to a flat mount of the third gen.... we shall see, might have to exchange for a third gen
but haven't come any REAL answer as to what i need to change. Also hear problems with "spongy" feel. What can i do to fix this now? FWIW I'm doing this cause the LS1 booster sits closer to the firewall and I'm trying to make more room in the engine bay. Also would a LT1 booster work as well? I have a complete LT1 Booster and MC. Thanks for the help. 
thanx for the correction.
