Quote:
Originally Posted by P1800 ES
Thanks for the tips. On the back of your suggestion I contacted a radiator shop local to me and they recommended back washing with a pressure washer and if that doesn't work then re-coring is about half the cost of a new rad, so that's also an option.
I've read up on the bleeding process and have a vacuum bleeder, so hopefully that will be successful. I've read other peoples frustrations with bleeding the brakes so hopefully it goes ok for me.
One thing I have been thinking about is whether I connected the lines at the front as they were originally?! Does it matter which circuit the flexi lines are connected to?
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Re-coring would be the expensive option. The radiator repair shop I used had a tank of heated caustic that they immersed the radiator in and let it soak. Upon removal they neutralized the cleaner and then washed the radiator. In addition to cleaning the core it removed all the paint on the rad and all the dead bugs in the fins. I would check other shops to see if they offer the dip option. Perhaps local environmental regulations are such that they are no longer able to use the caustic cleaning solutions in which case I would definitely try the back wash option.
I also have a Honda NSX for which I did not have a pressure bleeder adapter cap for the MC reservoir so I had to use a hand vacuum pump method to bleed the brakes. Whether it was because of the ABS system or just the nature of the beast, sucking brake fluid out the bleed ports was incredibly slow, taking about 30 - 40 min at each wheel before I started getting clean fluid. It was also painful - I ended up with an incredibly sore right fore arm and vowed to get an adapter. I have always used the pressure bleed on my 142 and from dry system to finished was less than 45 minutes.
Theoretically the line connection does matter. On the 140, one brake circuit is connected to the leading pistons and the other circuit is connected to the trailing pistons in the front caliper. If you mix the lines on both sides of the car then you have switched the primary and secondary circuits on both wheels. In that case you probably don't have a braking issue. If you switch the lines on just one wheel then you have the primary circuit going to the leading pistons on one wheel and the trailing pistons on the other wheel (and vice versa for the secondary circuit). Both circuits should operate at the same pressure so when everything is AOK that should not create a problem. However, if you have a failure on one circuit the leading / trailing piston mix may create a slight brake steer problem. However, put that in the context of a modern car with a dual diagonal brake system where a hydraulic failure on one circuit completely loses one front caliper and generates a whole lot of brake steer.
I think the bigger problem with switching the brake line connections may be the fittings. My exceedingly fuzzy recollection is that because of the little external hard line connection to the lower pistons on the front caliper, the fluid fittings are different - both at the caliper and the bulk head fitting mounted on the body. If you switch the hoses / hose ends they will screw in; but, they will not seal properly. Also, on the 140, depending on how you switched the hoses I think you can end up with hose bind if you run the suspension through its full range of motion.
On my 140, during its restoration I had a period of about 4 years from the disassembly of the brakes to final reassembly and I did not have a good picture of the hose arrangement at the bulk head fittings and did manage to reverse the front brake lines. The brakes worked; but, the fittings had a perpetual leak and I did manage to damage the flares on at least one of the fittings on the bulk head. It was only after another 140 owner provided me with photos of the bulk head installation and hose arrangement that I figured out my botched job. Been there, done that, got the tee shirt!
The comment about removing the contact portion of the brake failure switch is valid and absolutely necessary if you use the pedal pump method to bleed the brakes. If you use a pressure bleeder or a vacuum bleeder the pressure differentials you create in the two circuits are small (less than 14.7 psi) and the actuating piston in the brake failure switch will not move. However, it only takes about 1 min to unscrew the switch contact from the distribution block so easy to do if it makes you feel better. I have never removed it when using the pressure bleeder to flush the system on the 140.