| Author |
Message |
Rob Schermerhorn (Rexrcr)
Junior Member
Username: Rexrcr
Post Number: 207
Registered: 11-2002
| | Posted on Friday, February 07, 2003 - 7:46 am: | |
Speaking of torque specifications, brake bleeders on 348, 355, 360, F40, F50, Challenge Brembos, most other true racing calipers:
Torque bleed screw to 13 ft-lb.
We actually use a small torque wrench, it works, and beleive me, I was reluctant to change to the torque wrench until I realized the bleeders were "pushing" aluminum threaded bores further open due to over-torque. I saw two calipers on different cars crack for this over-torque reason. I am a convert now. |
billy bob (Fatbillybob)
Junior Member
Username: Fatbillybob
Post Number: 194
Registered: 8-2002
| | Posted on Thursday, February 06, 2003 - 8:28 am: | |
I have said it before and I'll say it again. Look for yourself at Ferrari Bosch electrical connectors and Ferrari ATE or Brembo Bleeders. Bosch, Ate etc...claim to only have one level of part but I swear Ferrari buys the "seconds." Feel them rock in your hand as you wiggle the connectors. BMW's bosch connectors don't do that. Try for yourself. That's one major reason for our electrical problems. Feel the threaded bleeder rock in the bores. They don't do that on BMW's or P-bugs. Ferrari bleeders literally suck. They suck air...when you open them too much. I've worked P-bugs and Ferraris and there is a huge difference in level of precision. Sorry just my 02 cents. Not meaning to offend.
<<btw,>>
Well kind of. You can do lots of things with these cars. You can still trap air as you sloch fluid around as you empty the master. Exposing any orifice is a potential air bubble. The clutch orifice is a really stupid design. Your comment while technically true is similar to just a "severe and reconnect" of the break points when doing an engine R&R in theese cars. It "works" to not bleed until the air works its way to critical points. Then the customer comes back miles later and you can charge them for a clutch or brake bleed. I've seen that done in less than stellar shops. The realites are that if you expose the orifice you potentially trap air. The way people work encourages trapped air. Personally, if I bleed brakes I Bleed clutch. Why have clean brake lines and dirty clutch line? I'm also a weird mechanic. Nuts are either on to spec or off. I have seen many a failure due to a hand tight nut thought to be torqued but forgotten. That kind of safety is just what a customer pays for in a quality shop. You can learn alot by watching others work. I'm not a pro BTW...and no implying that you would bleed in this way. I understand your point but there are many rookies on this list. They can take shortcuts when they understand a bit more about the compromises and possibilites written here. Until then it is best to stick to basics.
<<as>> |
Lawrence Coppari (Lawrence)
Member
Username: Lawrence
Post Number: 492
Registered: 4-2002
| | Posted on Thursday, February 06, 2003 - 8:23 am: | |
The large reservoir pressure bleeder sounds good but the previous comment about fluid getting stale and absorbing moisture holds. That is why I don't use it.
I use a pressure bleeder but I fill brake reservoir to brim with new fluid first. Then I use air to pressurize. Before I get through I have to refill the reservoir. |
Rob Schermerhorn (Rexrcr)
Junior Member
Username: Rexrcr
Post Number: 205
Registered: 11-2002
| | Posted on Thursday, February 06, 2003 - 6:20 am: | |
Bob, just try it, dude. The screech may be something else, you have to experience it, see what it takes to make the sound. Cycle the pedal, see what happens. BTW, if you do drop the reservoir level below the fitting for the clutch, you're fine as long as you don't go bleed the clutch without topping up. That system's hydraulics are closed, so the level doesn't get sucked out if the brakes are bled and the level drops in the reservoir.
As for bleed screws, the Ferrari calipers on the 348 are the same OEM Ate' and Brembo's as Porsche and others use. IMO, I don't think they suck.
One other tip for extreme cases only. Especially for the clutch hydraulics, but also for the brakes, if while bleeding, you suspect there remains a volume of air in the system, and conventional bleed procedures are ineffective, I pressurize the reservoir with nitrogen, regulator set down to 10 psi. I purchased an adaptor Mac Tools sells for their pressure bleeder, and I put an air coupler on the adapter. With the reservoir slightly pressurized, crack the bleeder open and watch the fluid and air come out. This method works if you suspect the cup seal in the master is not sealing and therefore not pushing any fluid. I have rescued many race events using this procedure. Otherwise, you may be looking at replacing the master, and if you're at the track with no spare, then what?
This is not an endorsement of pressure bleeders that use huge fluid reservoirs, the fluid gets stale, absorbs water quickly, fine for chevys, not for race cars or track cars. |
billy bob (Fatbillybob)
Junior Member
Username: Fatbillybob
Post Number: 190
Registered: 8-2002
| | Posted on Thursday, February 06, 2003 - 12:35 am: | |
No maky any sence? If you get screach on the rear you need to pedal only an inch? But you need to cycle the fronts as normal? How do you do this at the same time for one whole side?...The answer is you do it like I said below. Ferrari bleeders suck. if you open them up too much you suck air in because the threads have too much clearance. You do not have to worry about the volume the ABS pump can pump because you should be cracking the bleeder and controling the flow at the bleeder while the second man stokes the pedal. The reason to monitor the level is obvious but more importtant because on 348/355 some of the reservoir tamks have the clutch master opening in the upper 1/3 of the reservoir. Then you have to bleed the clutch if you suck are in there.
<< The pump running only reduces the effort to bleed the fronts, though. For the front, you must still cycle the pedal as in any other brake system. The rears with the pump on, you only need to depress and hold for a couple of secconds with somone monitoring fluid flow out of the bleed screw. If you depress too much in the rear circuit, you can actually here a screaching sound, possibly cavitaion due to increased fluid velocity. This is why one must only depress the pedal an inch or so with the rear brakes.
What my team always did (we had the manpower and not the time) was one side of the car at one time. One guy right front, one guy right rear. Sychronized by calling out "open...closed...open...closed" >> |
David Burch (Merlyn)
New member
Username: Merlyn
Post Number: 42
Registered: 8-2002
| | Posted on Wednesday, February 05, 2003 - 2:19 pm: | |
Thanks Rexrcr, I understand the necessity of bleeding one side at a time when doing a balance bar system, never thought it necessary with a tandem master cylinder, but I do see the logic, full strokes if both bleed screws on the same side are opened at once. |
Rob Schermerhorn (Rexrcr)
Junior Member
Username: Rexrcr
Post Number: 204
Registered: 11-2002
| | Posted on Wednesday, February 05, 2003 - 1:56 pm: | |
With key on, (actually, one only needs to slowly turn the key, at a point before the guages light up, the pump will run if pressure in the system has dropped slightly) you only need to depress the brake pedal an inch to get the fluid moving out the rear bleeders. The pump running only reduces the effort to bleed the fronts, though. For the front, you must still cycle the pedal as in any other brake system. The rears with the pump on, you only need to depress and hold for a couple of secconds with somone monitoring fluid flow out of the bleed screw. If you depress too much in the rear circuit, you can actually here a screaching sound, possibly cavitaion due to increased fluid velocity. This is why one must only depress the pedal an inch or so with the rear brakes.
Also, remember, first the inboard bleeder, then the outboard. Many say to begin furthest from the master cylinder (right rear for LHD) and do one caliper, one bleeder at a time. What my team always did (we had the manpower and not the time) was one side of the car at one time. One guy right front, one guy right rear. Sychronized by calling out "open...closed...open...closed" with the guy in the driver's seat, we did first both inner bleeders on one side of the car, then both outers on one side. Repeat for opposite side of the car. Made no performance difference whether we did right or left first.
Have fun. |
David Burch (Merlyn)
New member
Username: Merlyn
Post Number: 41
Registered: 8-2002
| | Posted on Wednesday, February 05, 2003 - 10:12 am: | |
Thanks all, Are you saying that if you turn the key on the ABS pump will force fluid through the bleed valves without pumping the brakes? |
Rob Schermerhorn (Rexrcr)
Junior Member
Username: Rexrcr
Post Number: 203
Registered: 11-2002
| | Posted on Wednesday, February 05, 2003 - 7:22 am: | |
JRV's not kidding to watch the reservoir. You can run it dry with the ABS pump in 15 seconds of the pedal down while bleeding the rear calipers. |
billy bob (Fatbillybob)
Junior Member
Username: Fatbillybob
Post Number: 185
Registered: 8-2002
| | Posted on Tuesday, February 04, 2003 - 11:44 pm: | |
Bleed like regular car but in the key position ABS pump runs or with car started. Takes 15 mins. This makes it easy to bleed system when you energise the ABS. IF you don't do it this way you can still trap air by inefficient bleeding...but it can be done with key off...but hey if you got power tools use em! |
JRV (Jrvall)
Member
Username: Jrvall
Post Number: 819
Registered: 11-2002
| | Posted on Tuesday, February 04, 2003 - 10:56 pm: | |
>>This system opens the ABS valves so the whole system gets bled.<<
On these systems you can turn the key to # 2 position (until the ABS pump runs) then slowly & carefully bleed (by Rics description) while the pump cycles. Also there should be a note in the WSM describing how to turn the pump on for testing purposes that can slso be used for bleeding.
Be careful not to allow fluid resivoir to empty. |
Mitch Alsup (Mitch_alsup)
Member
Username: Mitch_alsup
Post Number: 328
Registered: 4-2002
| | Posted on Tuesday, February 04, 2003 - 10:42 pm: | |
The 1997 manual indicates that the ABS system is attached to a brake diagnosis system (SD-1). This system opens the ABS valves so the whole system gets bled. |
Ric Rainbolt (Ricrain)
Member
Username: Ricrain
Post Number: 461
Registered: 2-2002
| | Posted on Tuesday, February 04, 2003 - 10:37 pm: | |
I bleed my 348 just like any other car, and the brakes work very well. The 355 brakes are virtually identical.
Rear right, rear left, front left, front right. |
David Burch (Merlyn)
New member
Username: Merlyn
Post Number: 40
Registered: 8-2002
| | Posted on Tuesday, February 04, 2003 - 6:47 pm: | |
I need to bleed brakes on a 99 355. Are there any tricks, or do you just do a normal bleed procedure? I am concerned about the ABS system. |
|