Hi, Picked up a 348 US spec spyder last december. Starting to sort some things out. The car had a rock hard (basically in op) brake pedal/no brakes. 1. None of the calipers are frozen. 2. I can crack any of the front four bleed screws and bleed and/or pump out fluid with good pedal travel no problem. 3. Close front bleed screws and open one or all four rear bleed screws and I get a little fluid via gravity bleed, but hard/in op pedal returns and I cannot push fluid out the rear calipers the way I could the front because of no pedal travel. I've got a used but working Jaguar ABS pump and conversion kit that I have not installed but thats just the ABS pump. The brakes should work and the pedal should travel even if the ABS pump fails or is IN OP correct? Additional info ABS light is on. Code reads 25 or 26 depending on how you count the last flash. Last flash light stays on solid for 6th flash so if you dont count that its code 25 Thanks
Thanks, No dice with power. Still unable to depress pedal and push fluid out the rear calipers with ignition on or car running. I can here the pump running. Tomorrow I'll swap in the other pump to see if there is a difference just to eliminate some variables. I'll review those videos too thanks
How long does pump run? It's typical 5 seconds or so. If it's longer accumulator could be bad. Sent using FerrariChat.com mobile app
I could pry the pistons F & R back into the calipers. Fronts returned under brake pressure. Rears went in but wont return since there seems to be no outward pressure.
Could have a very badly maintainted system. I would then go through it top to bottom. Possible rear lines are collapsed. No fluid out bleeder in rears? Y= caliper problem need rebuild N=fouled bleeder remove it poke hole with wire fluid comes out? Y= fouled bleeder and caliper internals need rebuild. N= collapsed lines? severe connection at rubber to hardline interface fluid comes out with pedal? Y= collapsed rubber lines N= severe at next connection and retest.
The pump should stop running after approx. 5-10 sec. The fact that your pump runs all the time suggest that it has some fault, possibly unable to build sufficient pressure to trigger the pressure switch to "off" position. Otherwise, when braking, the pedal (pushrod) movement is transmitted directly to the piston for the front brakes but the force applied to the pedal is, inside the MC, helped by the hydraulic pressure acting on the pushrod. At the same time, the rear brakes are operated directly by the hydraulic pressure which is "modulated" (amount of pressure controlled) by a special mechanical valve inside the MC which, in turn, is controlled by the pushrod movement. It might be the case that your pump produces very low hydraulic pressure, thus low flow to the rear brakes. When bleeding the rear brakes, you are not actually "pumping" the fluid to them like in conventional braking systems, you are just operating the mechanical valve inside the MC to allow the pressure built by the electric pump to go to the rear brake caliper pistons.
Definitely pressure issue to start with. Accumulator, pressure switch, relays, pump itself etc etc. Do you have a brake light on the dash illuminated?
My vote is collapsed rear lines as well. They are rubber and they swell internally. Very rare that both of them would go at the same time but this exact precise thing happened on my 328 on one side.
Very inexpensive and also very easy to check simply remove the rubber lines and try to blow through them.
Thanks for all the input so far. As an update 1. swaped in the new (used/assumed working pump) no change to ability to move pedal or get fluid out of the rears calipers 2. I left the Drivers rear caliper bleeder cracked last night and almost 2 quarts passed through from the reservoir to the catch basin. 3. Pulled, cleaned all the ABS wheel sensors. Rears had some gunk and varnish on them. Cleaned the connections. tested resistance on all 4 sensors, they had between 1.105-1.136 resistance. I tested by probing the center ring and then touching the outer serated ring of teeth in the connection going to the hub. 4. powering up the car: the pump has a two pitch whine for 5-10 seconds whee-whaa, whee-whaa (bad description after that it changes to a a solid mono tone/sound and continues to run (and also gets a little warm.) 5. No red "brake" light on on dash 6. ABS code still flashes 6 times on second sequence with 6th time staying on solid. In researching old threads on this some say you can disable the ABS pump and the brakes will work just without the anti lock function? Is this ture? if so how? Just unplug the ABS ECU? Thats fine if this is an ABS issue needing time to get parts or sensors etc. Looking for a short term fix here to get the car more mobile/useable until them if possible Thanks!
"continues to run" does the pressure switch detect pressure and send stop signal? Its a Delco switch btw.
I had to stop for the day because I'm trying really hard not to drink So I took the pressure switch from the OEM pump, installed it in the Jaguar pump and after about (at least) 45 seconds it did stop running (achieve pressure). The pump changed tune several times and I thought maybe I had burned it up so I relieved the pressure and re powered the pump and yeas it re pressurized and stopped running. So Pump created and held pressure pump stopped running ABS light is now off I get drops of fluid out of the rubber lines to rear calipers but I still have zero pedal travel when all bleed screws are closed, or pump powered and rear screws open or lines disconnected from calipers. Seems to ne like something internal in MC would be corroded/blocking the lines to the rears, but why would I get fluid out of the rears but cant push it (more fluid) via the pedal?
Do you mean the brake fluid is seeping out of the rubber hoses? If this is the case, replace them immediately. Old brake rubber hoses are known to swell and almost completely block the fluid flow.
No I physically disconnected the rubber lines from the calipers and got fluid dripping out the metal fitting/screw on the end of the hose. Same rate/flow as it drips out of the bleed screws on top of the calipers, so i know there is flow from the reservoir to the rear calipers just no flow with of any sort of force
Might be a stupid suggestion; but physically trace all the brake lines. By the sounds of it especially the rear. As with all cars the original pipes are steel and can corrode; and also there are some unions at the back of the car that can be easily damaged by a ham fisted mechanic. As you are deep into it, might be worth disconnecting the brake lines at the front manifold and at the callipers, in turn, and blowing some compressed air through the lines?
Remove the rubber brake hose completely from the car and see what comes out of the metal brake line. That is the only way to see if it is the rubber hose like Miro suggests.
Bizarrely, I too have a challenge here in the UK with my European spec. 348 Spider. I've just gone through the annals of 348 threads and can't see anything similar, which both surprises and frustrates me, because I've found 9 times out of 10 someone on here has already fixed whatever I'm trying to resolve. I'll post a new thread request, but if the answer does already exist somewhere else, hopefully someone will simply direct me towards that url., rather than cut me off at the knees.
Today's update. Rechecked wheel sensors and cleaned toothed ring inside hub. ABS sensors show both resistance and trace voltage being sent back. Pump is working fine, creating, holding pressure and shutting off. I physically disconnected the hard line that feeds the rear calipers for the bottom of the MC. With this line disconnected I still cannot move the pedal. With pump producing pressure and that line open I should get significant fluid out of the bottom of the MC just like I get significant fluid out of the MC if I disconnect either of the hard lines that feed the fronts. Back to the code it was throwing of "26 rear delivery, rear inlet valve". Next step is to research/find this rear inlet valve. Is it inside the MC? Powered by a relay or a fuse to check?. All the fuses (30a/30a/3a) are fine at the ABS ECU. The lines both hard and rubber supplying the rear calipers are flowing. I'm not getting fluid (it is s light drip) out of the bottom of the MC in the port that supplys those rears lines.
