2001 vs 1997 brake master E350 differences?
- Thread starter Bikersmurf
- Start date
Bikersmurf
Expedition Leader
At this point, the real question is are the brake lines connected the same way? To clarify, does the front port on both brake masters go to the front brakes? And the rear to the rears?
The reason I ask is that the two fittings aren't the same size, and they are reversed between the two Master Cylinders. Does anyone know it the fittings on the ports of ABS control 'Block' can be interchanged... or it taking them out is opening a can of worms?
To proceed, I see two main options:
1) remake the lines, and swap the ends so that they hook up the same way.
2) make new lines and reroute the lines so the connections are reversed.
@Ujoint
@MgMetalworks
The reason I ask is that the two fittings aren't the same size, and they are reversed between the two Master Cylinders. Does anyone know it the fittings on the ports of ABS control 'Block' can be interchanged... or it taking them out is opening a can of worms?
To proceed, I see two main options:
1) remake the lines, and swap the ends so that they hook up the same way.
2) make new lines and reroute the lines so the connections are reversed.
@Ujoint
@MgMetalworks
Last edited:
Bikersmurf
Expedition Leader
I have confirmed that the 2001 Master is 1 5/16". The larger master should be a positive thing.
Instalation shouldn't be an issue so long as the booster and master are installed as a set. All that leaves is confirming the connections.
Instalation shouldn't be an issue so long as the booster and master are installed as a set. All that leaves is confirming the connections.
naterry
13 Cheeseburgers
I don't know if the front port goes to the front brakes or vice versa because there is no rule of thumb. Some MC's are Fr/Fr & Rr/Rr, some are the opposite. One rule of thumb does apply and that is that the port with the corresponding larger reservoir chamber (note the reservoir is split into two chambers) usually goes to the front brakes, and this usually has a larger fitting.
Regarding MC piston diameter; as the diameter increases, so does the required input force for the same brake line pressure. In other words, going from 1.25" dia to 1.3125" dia will make the brakes *feel* weaker. Perhaps the new booster that came with the larger MC is larger and thus compensates for this? It's worth considering, and comes into sharp focus when you stall the van on a steep windy trail and have to hold it sans boost assist...
Another way to put it would be to consider a 100lbf input force for the two MC dia's:
Brake line pressure (P1) given 100lbf input on a 1.25" dia MC:
P1=100lbf/(3.14 x (1.25/2)^2)
P1=81.5psi
Brake line pressure (P2) given 100lbf input on a 1.3125" dia MC:
P2=100lbf/(3.14 x (1.31/2)^2)
P2=73.9psi
Regarding MC piston diameter; as the diameter increases, so does the required input force for the same brake line pressure. In other words, going from 1.25" dia to 1.3125" dia will make the brakes *feel* weaker. Perhaps the new booster that came with the larger MC is larger and thus compensates for this? It's worth considering, and comes into sharp focus when you stall the van on a steep windy trail and have to hold it sans boost assist...
Another way to put it would be to consider a 100lbf input force for the two MC dia's:
Brake line pressure (P1) given 100lbf input on a 1.25" dia MC:
P1=100lbf/(3.14 x (1.25/2)^2)
P1=81.5psi
Brake line pressure (P2) given 100lbf input on a 1.3125" dia MC:
P2=100lbf/(3.14 x (1.31/2)^2)
P2=73.9psi
Bikersmurf
Expedition Leader
Yes, as the diameter increases so does the force to apply. Given the Master and Booster came off the exact same vehicle, with the equivalent upfitting, I'm sure this won't be a problem. Travel has been a problem though.
Bikersmurf
Expedition Leader
I haven't been able to find out any information about the relative function of these two masters.
What I do know:
1) the Front Calipers look the same (and I'm using the 2001 already Calipers).
2) the Rear wheel cylinders are the same for 97 & 01.
3) the ABS units are the same for 97 & 01.
4) boosters are different (97 vs 01) and not interchangeable.
5) master cylinders are different (97 1 1/4" vs 01 1 5/16") and not directly interchangeable.
So... I'm going to swap the master and booster together and have custom lines made to connect the 01 master the same way the 97 was connected. Both lines will be made the same length so that if they need to be reversed, the ends can be swapped and the lines re-routed. I'm hoping to install the parts and bleed the brakes only once...
Backcountry Pursuit
Risk Taker
I have a similar mess going on. I have a 98 van. I am pulling the booster, MC, more advanced abs module and wiring out of a 2000 parts van. That is going in my 98. It's getting MG's conversion up front with the massive discs that are on the 2015 front axle I have. I am also installing a Sterling rear that takes my 98 from drum to disc in the back. I will know a lot about brake systems when I am finished. I am hoping since I am scavenging the entire system it should go smoothly. However, nothing had gone smoothly thus far.... When I dig into this in a few weeks I'll check back in here to compare notes with you.
Bikersmurf
Expedition Leader
Answer:
With the new custom lines connected to the same locations the brakes work awesome. I'd swap them again in a heartbeat.
Is it worth swapping a good master & booster to go from 1 1/4" to 1 5/16" can't say for certain. Would I replace a old master and booster for a newer larger one... Certainly. The brakes feel way better than ever before... It now feels over braked as opposed to having ok brakes.
I've driven a lot of bigger vehicles with ok brakes... I was coming to accept that's just the way they were... Not so. The 01 master makes the 97 perform well... Was the 97 master tired? Probably. Under performing or just to old? Don't know, don't care.
With the new custom lines connected to the same locations the brakes work awesome. I'd swap them again in a heartbeat.
Is it worth swapping a good master & booster to go from 1 1/4" to 1 5/16" can't say for certain. Would I replace a old master and booster for a newer larger one... Certainly. The brakes feel way better than ever before... It now feels over braked as opposed to having ok brakes.
I've driven a lot of bigger vehicles with ok brakes... I was coming to accept that's just the way they were... Not so. The 01 master makes the 97 perform well... Was the 97 master tired? Probably. Under performing or just to old? Don't know, don't care.
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