| Author | Message | ||
     George Constantine Experienced User Username: theo Post Number: 15 Registered: 6-2012 |
Hi all, A puzzling thing happened for the second time now. On a 1979 Corniche. When slowly driving up a steep hill for a while (The very steep hill in Richmond Park)I get a rubbing/burning on the N/S/rear wheel. The area around the wheel/hub got so hot that smoke started to bellow around the wheel. The brakes are not binding and the wheel hub and wheel are so hot they cannot be touched. I cannot see what causes this or how it occurs. After living the car to stand for a long time and driving on flat road it seems to be OK. I would be very grateful for any advice. | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 1202 Registered: 6-2006 |
Most often it is the trailing arm hoses closing up inside and not releasing the fluid from the caliper. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 807 Registered: 6-2009 |
George, I'm with Paul, but will add a bit more information from post I made elsewhere a long while ago: When driving the car you feel a clunking sensation that seems like a misfire (but you know the engine isn't misfiring). You are feeling the brakes activate when they shouldn't and you are not applying them at all. One possible cause is that the solenoid valve controls the speed of height control is energized at the wrong time, causing fast leveling behavior when it should be slow. More likely, though, is that you have a plugged restrictor valve that's causing fluid back pressure. You can also have the same issue, but without the clunking, if your return hoses from the calipers are collapsed (or collapsing and then eventually coming open again). This usually results in the brakes remaining "on enough" to cause things to heat up excessively, often to the point that the hubcap is hot or, in extreme cases, hot enough to melt the grease out of the bearings. The brakes need only be partially activated, and not nearly enough to stop or even slow the car, for the resultant friction heating to occur. Brian | ||
| Bob uk Unregistered guest Posted From: 94.197.122.78 |
Flexible brake hoses can act like one way valves as they deteriorate the inside collapses impeding the return flow of dot When the brakes are off the hoses ate directly connected to the brake reservoir So if the caliper bleed screws are opened dot should flow under gravity If it does not then most likely the hoses have collapsed If you have trouble getting them off Underneath the boot carpet are small plastic caps that cover the tops of the screws which hold the fittings to the boot floor The screws can be released from the top The hoses are max 20 quid each There is no advantage in aero type hoses The service life of hoses 5 to 10 years both types (Message approved by david_gore) | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 809 Registered: 6-2009 |
Bob, Depending on what you mean by "aero type hoses" I have to beg to differ. If you mean PTFE core hoses I definitely disagree. The internal degradation and ultimate collapsing of conventional brake hoses is secondary to a long, slow interaction between the hose material and the brake fluid. Newer PTFE core hoses eliminate that entirely since PTFE is inert. Since most of these also include stainless braiding (which is really unnecessary in low pressure applications, but "comes standard") and many have another protective sleeve on top of the stainless. These have a far longer service life than conventional hoses and, given the ungodly tedious nature of replacing the full set, are more than worth the slight increase in cost in my estimation. Brian | ||
| George Constantine Experienced User Username: theo Post Number: 16 Registered: 6-2012 |
Thank you all for your input. I'll check all that you mentioned. Will this problem only occur when climbing up a hill though and not on an even road and wont both sides be effected? Cheers George | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 810 Registered: 6-2009 |
George, Both sides will not necessarily be affected. When these hoses age and begin their interior collapse that can happen at differential rates. My guess is that you've got a bad hose for one piston on one rear caliper, and that's all it takes to create precisely the frictional heating situation you describe. I really don't get the "only occur when climbing up a hill" part but I haven't gone through all the "what if-s" to come up with a possible explanation for that. Brian | ||
| richard george yeaman Prolific User Username: richyrich Post Number: 161 Registered: 4-2012 |
George if you have owned the car for more than five to ten years and haven't had your hoses changed I would change them as a priority. It would help in preserving life and limb!!!!! Richard. | ||
| Bob uk Unregistered guest Posted From: 94.197.122.73 |
The stainless braided jobbies do last much longer but the fly guys These guys are seriously anal when it comes to aero stuff tell me 10 years. Max. They are not difficult to change Aero type are fine to use Bedford C.F. Van ones fit rubber To me the aero ones look good The main reason for the use of aero hoses is that some imagine that rubber expands a lot it doesn't The feel of the pedal is subjective The power is the same The feel of the shadow brakes are artificial on the SS 2 and 16# on the SS 1 If you like cool looking bits under the boot floor then fit aero Aero are not much more money Be carefull in sub zero temperatures. Be carefully with stainless threads galling I made a threaded whatits out stainless and hand fitted it to another stainless thing and overnight it seized When I got it apart the threads had picked up. Galling So do use thread lub (Message approved by david_gore) | ||
| Bob uk Unregistered guest Posted From: 94.197.122.73 |
Error Car aero hoses are not the same as hairy planes And are not temp sensitive (Message approved by david_gore) |
