| Author | Message | ||
     Matt stroud Experienced User Username: stroud234 Post Number: 15 Registered: 10-2018 |
Hydraulic leak hi everybody have posted before about noisy rear brake pump and leak as discussed before I thought the rear brake pump was leaking and that was one of the reasons why the pump was noisy took carburettors off last weekend to check brake pump it wasn’t leaking I’ve had the car for about a year now and probably done 2000 miles I have put over 3 L of brake fluid in it but can’t find any traces of a leak even brought to post car lift ( as discussed in another post ) to try and find it for that amount of fluid to come out you would think you could see it quite easy don’t know if anybody could throw some light on this for me please as I’m stumped | ||
| Mike Thompson Experienced User Username: vroomrr Post Number: 11 Registered: 4-2019 |
I know nothing about these brake systems (free advice, you get what you pay for). It has to be going some where, as inside the engine (not good) or inside the lifter housing etc. | ||
| Omar M. Shams Grand Master Username: omar Post Number: 1809 Registered: 4-2009 |
Dear Matt, Oil will go somewhere and leave a trace. please check your engine oil level. Is the level correct or slightly high? the most challenging thing would be if the hydraulic pumps leaked internally into the engine and the engine also consumed the exact same amount of oil masking the whole problem. Does the engine oil feel like it is good oil when you touch it and smell it or do you think there may be contamination with hydraulic oil? | ||
| Steve Emmott Prolific User Username: steve_e Post Number: 196 Registered: 11-2018 |
Matt, I can't see the exact year of your car. I can see you are close by me though in North Lincolnshire. I suggest you take the 'rat trap' cover off under the floorpan RHS underside of RHS seat area. Just check for any signs of fluid on the inside of the cover as it tends to disperse as you are driving leaving little signs of any leak when you park up. IIRC there is a natural small leak around the valves that can be expected but I would have to check my grey cells here as a long time since I rebuilt mine. I have all the correct factory tools for the Shadows general repairs if needed. | ||
| Steve Emmott Prolific User Username: steve_e Post Number: 197 Registered: 11-2018 |
Matt did you just change something as suddenly I saw High Wycombe in your profile........must be the wine or something froze on my computer  | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2814 Registered: 6-2009 |
Steve, You are absolutely correct that there is supposed to be "controlled seepage" from the distribution valves in the rat trap. It's common to have a drop of RR363 hanging from them (see the Distribution Valves chapter of the Workshop Manual). The rat trap cover on SRH33576 had a small "crust" on the inside surface immediately below the distribution valves where each would drip (very slowly, and over years) and the fluid dried up. If you have a big wet puddle or it seems like there's been a "river running through there" on the inside of the cover something's wrong. Brian | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 16 Registered: 10-2018 |
Hi yes taken rat trap off and no evidence of leakage engine oil seem all fine but if the pumps can leak into the engine oil I would say that’s the only place it could be going and it is 1978 Silver Shadow two if it is a leaking pump would it be from the o rings ? And yes I live in high wycombe | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 17 Registered: 10-2018 |
hi Mike if you know nothing about these brake systems then Your free advice means nothing as you don’t know how much I pay for the car | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 381 Registered: 5-2016 |
Hi Matt, If the 2 large O-rings between the pump and the pump housing were leaking you would see a drip around the top or bottom of the housing and a trace of fluid down the back of the engine. If the smaller seals inside the pump had a leak the fluid would go into the engine via the pump pushrod and that would be difficult to detect. I've read somewhere that the cork filter under the oil filler cap can develop a shiny glazed appearance if brake fluid leaks into the engine oil but I have never seen that personally. Another place you could check is inside the boot/trunk at the top of the suspension turrets where the pipe connections from the height control rams to the height control bleed screws are located. If there's a leak there you will see traces of fluid in the carpet (not good for the paintwork). The height control bleed nipples are another thing to check for leaks, the brake pressure switches and the spheres and accumulators. The flexi return hoses to the reservoir and the flexi feed hoses to the pumps are another regular culprit and check under the reservoir for drips. It sounds like you have an internal leak at the pump but eliminate everywhere else first. | ||
| David Gore Moderator Username: david_gore Post Number: 3200 Registered: 4-2003 |
Larry, If the fluid is getting into the engine, I suspect the colour and smell of the engine exhaust gas would be different. I would be undertaking a full inspection of all the hydraulic system components and the underside of the car for fluid leaks remembering RR363 is miscible with water and any leak traces might have been washed away after driving on wet roads. . | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 383 Registered: 5-2016 |
Yep David, or leave the engine running for 10 minutes while parked on a plastic/polythene sheet and with the brake pedal depressed and any external leaks should become apparent. | ||
| Mike Thompson Experienced User Username: vroomrr Post Number: 21 Registered: 4-2019 |
Matt Stroud I don't care what you paid for your car, but personal remarks are inappropriate. I was only light heartedly trying to help. | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 18 Registered: 10-2018 |
Cheers guys as it’s on two post car lift I have checked all the places you have mentioned had it running for quite awhile and has been on plastic sheet as I mentioned in previous post about noisy pump and traces of oil by The distributor that’s why I thought the pump was leaking but there was no trace on the outside of the pump so the only conclusion is it’s leaking inside | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 384 Registered: 5-2016 |
If the rear wheels are dangling while the car is on a 2 post lift the pressure will be off the rear suspension and any leak in that area might not be as evident as it would be when the car is resting on it's rear wheels with the rear height control rams depressed. Worth a check just in case. | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2816 Registered: 6-2009 |
Also, as noted, the brake pedal will need to be depressed and stay that way during stationary testing if one wants to see if a leak is present somewhere. Though it is absolutely not impossible for there to be an internal leak from the pumps into the engine, it is highly unlikely. The probability of a leak elsewhere is far more likely. Brian | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 19 Registered: 10-2018 |
Larry Brian thanks for that didn’t have the brake depressed I will do that next and uncouple the rear height controll arms before l tackle pump the only thing can’t quite understand is to lose over 3 litres in that amount of miles you would think it would easy to see will let you know how I get on | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2819 Registered: 6-2009 |
Matt, Brake fluid is a lot more volatile than motor oil is. (Just try, carefully and with very little of it, to light it on fire and you'll see how much more amenable it is to burning - don't ask about how I know that). Depending on where it might be escaping and what it might be hitting the leak might be hard to find. If you were leaking that much into the engine your oil level should rise. That's an awful lot of fluid. Brian | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 386 Registered: 5-2016 |
Your engine oil level should show a significant rise if you lost 3 litres into the engine. Why are you going to uncouple the height control arms? | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 20 Registered: 10-2018 |
Hi Brian just put up on lift had brake on moved height control levers run car for over 20 mins not drop anywhere the pump is ticking quite loud it must be leaking if I change o rings while I gone to that trouble in yourOpinion is it worth putting a reconditioned pump in they are a couple of hundred pound | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 21 Registered: 10-2018 |
Hi Larry I thought if I Took off the height control levers and move them up and down it will pressurise it but the system and check for leaks | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2820 Registered: 6-2009 |
The height control arms will pressurize the height control rams, but those could be (probably aren't, but could be) leaking into the boot. This would be the least likely area to be an issue, particularly if you routinely drive the car unladen and the height control system is never activated. A ticking pump can be indicative of an accumulator that's low on nitrogen charge, too. Though even in that case the pump should eventually quiet down at least somewhat once the accumulator has enough fluid in it "pushing back" in the system and after the ACV switches to bypass mode. The rear brake pump on SRH33576 was very noisy indeed when the accumulator had become depleted of nitrogen, as the nitrogen charge acts as a sort of damper on the system as a whole when it's in charging state. It's not unlike the way the Citroen suspension works, but in this case its the pumps, not the bumps, that are being smoothed out. Brian | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 22 Registered: 10-2018 |
Hi Brian done the brake pedal test on the accumulators and it takes at least 40 to get one like to come on and 60 or 70 To get the other light on so I thought they were okay or is there something I’ve missed | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 23 Registered: 10-2018 |
Hi Brian if the pump was leaking would that make it tick | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 2822 Registered: 6-2009 |
Matt, I will not say that leaking won't make it tick, but I also see no particular reason that it would tick unless the pump were so compromised that it couldn't really pump at all and as much would be going into the engine as to the accumulator control valve. These pumps tend to tick, and particularly if you have an accumulator that's low on charge. But your brake pedal test strongly suggests yours should not be in that state. Brian | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 387 Registered: 5-2016 |
The pump will tick if there's air trapped inside it. If you depressurise the system and then open the accumulator bleed nipple and attach a bleed hose into a jar any air in the pump might release when you start and run the engine. The pump should output about a 1/2 pint per minute through the ACV bleed nipple when the engine is started so begin with a full reservoir.Then close the bleed nipple but you may need to bleed the complete No.2 system afterwards. Sometimes the high pressure pipe from the pump to the ACV if not correctly fitted can create a tapping sound which is caused by cavitation or from the pipe rattling against another component e.g., the carb intake elbow. | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 24 Registered: 10-2018 |
Ok Larry might have air insyterm if fluid is coming out then air might get in ( still got to find leak) I think the pump has to come off | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 389 Registered: 5-2016 |
OK Matt, The pumps can be rebuilt with a new spring and seal kit if not too badly worn. If you take the pump out remove the push rod and check it for any wear, if there's any damage whatsoever replace the pushrod as they've been known to break if there's a weak spot. | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 25 Registered: 10-2018 |
Cheers larry | ||
| gordon le feuvre Prolific User Username: triumph Post Number: 298 Registered: 7-2012 |
When the factory first changed to rigid pipes from pump to accumulators (they could not stop the flex pipes from chafing as they moved on each stroke of pump). I guess ALL cars were modified from 1001, I personally did over 40 cars! Did loads work with factory on stopping "brake pump knock" that manifested it's self when pump working to build pressure, usually noticeable after using brakes/stopping. The cause was the conical non return valve in pump. If ANY marks on cone or not seating, this made all the difference to noise level. Messed about with run of pipes/ different valve bodies as well, but noise never really went away. Owner complaints really were based on driving style, if owner used brakes a lot and then took off again at slow speed, it would be more pronounced, drove with radio off, windows closed etc | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 412 Registered: 5-2016 |
Did you get it sorted yet Matt? | ||
| Matt stroud Experienced User Username: stroud234 Post Number: 26 Registered: 10-2018 |
Hi everybody I rang flying spares and spoke to technical guy there he said sounds like the pump is faulty that’s why it is noisy so I brought reconditioned pump fitted it over the last week took it out for test drive today quiet as a mouse when I inspected the old pump it seems to me like the bottom spring had either worn or broke as for leak Hoping it had something to do with pump I will keep eye on that and report back | ||
| Larry Kavanagh Grand Master Username: shadow_11 Post Number: 435 Registered: 5-2016 |
Good result Matt, hopefully your leak is now sorted, happy motoring. Regarding the previous leak in the No.2 hydraulic system double check the bleed nipples for the height control rams when the height control is activated i.e., when there is a significant weight in the trunk with the rear wheels on the ground. If there is a leak at those 2 bleed nipples it might not show under normal unladen conditions but the nipples could emit fluid when the height control is activated by carrying weight in the rear or when travelling on bouncy roads e.g., driving over speed ramps. |
