Bongo Fury

I spent most of the day doing jobs around the house, like repairing the door loom on the dishwasher that's been broken for 3 weeks and doing some gardening.

Tonight, I rigged up Peter's spare header tank to pressure test caps, I had three in front of me. Two honked and my old one pfffed so I butchered it to make a cap to use to pressurise the Bongo's coolant system. I cut a schraeder valve out of a bicycle inner tube and jubilee clipped it to the overflow hose and jubilee clipped the hose to the overflow stub. I had the LCD propped up on the steering wheel (very short 12V cable) and had to scrape the ice off the windscreen and wipe the inside to be able to see it from outside. I used a bike pump to pressurise the system and went up to 10-psi or thereabouts each time.

With a bit of washing-up liqiud and water, I quickly found one leak that I puttied over. The last three tests from 400 to 628 on the graph below show what I'm left with (sample period 5s).



Van started in a stroke and settled quickly into a clean idle, still on 50% veg

The road test shown in the second half is still a very good sign, unless there is a now a leak elsewhere. I was driving it quite hard with several 40-60 pulls, the temperature needle was behaving and the pressure was gradually disappearing with no signs of really responding that much to driving conditions, other than idling my way through a couple of villages. I would have expected to see a much different graph with the system as it was a week ago, but due to the pressure leak, it's still not conclusive.

I'm quietly confident.

Found two more small leaks from the putty on the header tank. Putty isn't cutting it, it's leaking underneath so I'll try giving it a coat of JB Weld epoxy after lunch.

Driver+Passengers wrote:Found two more small leaks from the putty on the header tank. Putty isn't cutting it, it's leaking underneath so I'll try giving it a coat of JB Weld epoxy after lunch.

JB weld top-coat applied to the putty on the header tank with a small brush. Taking a while to dry in the open air- quotes 25 minutes and it's been coming on for an hour but it's probably a thickish coat and not sandwiched between anything.

Will get a pressure trace this afternoon, anyway. Topped up coolant level with water, so I imagine I might get high readings and/or push a bit of coolant out of the cap if it needs to find it's level. I'm going to be anxious seeing pressure rise to 16psi if it does, but provided temp stays stable and pressure settles, I'll keep driving. I might move the van to the level and measure it before I go.

Eyeballed the tracking and reduced by a turn on one side - had added two on each side to account for the track rod ends being shorter than the old ones, and the steering wheel has not been bang-on straight since I got it.

Fingers crossed.

good luck.

If all this works Matt you can buy us all a pint with the money you have saved when you finally get to Red Squirrel campsite.

Tony

Cheers!

Have to wait - epoxy is not hardening very quickly. I snipped a tin plate and pressed it over the problem area and daubed a bit more epoxy round it.

Will get booked in for tracking shortly.

MountainGoat wrote:If all this works Matt you can buy us all a pint with the money you have saved when you finally get to Red Squirrel campsite.

Tony

What about all the money that Matt has saved people with his FREE 'teach in'. I reckon we all owe him a pint.

Not much use if you can't understand what he is talking about. Those graphs of his are gobble de gook to me.

Tony

I'm quietly confident.

Let it be his epitaph

the whole idea of trying to get epoxy to stick to polythene sounds an uphill one to me: a polythene lunchbox top is precisely what I use to mix all my modellers epoxy, 38 etc. on because it can be cracked and peeled strsight off and the mixing surface re-used. Introduce hot coolant searching along the (weak) glue-line, under pressure, and trying to get epoxy to cure in cold weather, and it sounds like a Space Shuttle type incident waiting to happen. On the (very) plus side, everything else seems OK with the Bongo except for the minor business of the header tank and fingers crossed it stays that way oh and get that tracking done properly ASAP

mikeonb4c wrote:

I'm quietly confident.

Let it be his epitaph

the whole idea of trying to get epoxy to stick to polythene sounds an uphill one to me: a polythene lunchbox top is precisely what I use to mix all my modellers epoxy, 38 etc. on because it can be cracked and peeled strsight off and the mixing surface re-used. Introduce hot coolant searching along the (weak) glue-line, under pressure, and trying to get epoxy to cure in cold weather, and it sounds like a Space Shuttle type incident waiting to happen. On the (very) plus side, everything else seems OK with the Bongo except for the minor business of the header tank and fingers crossed it stays that way oh and get that tracking done properly ASAP

I agree on both counts.

I used a hair dryer to cure the epoxy - came up lovely! First cold pressure test found the only spot where the epoxy top-coat was incomplete, so I puttied it and started driving 10 minutes later.



The horizontal scale of this trace is much the same as the previous one, but lines will look a little steeper on this one. The sensor is quite 'noisy' so this trace is a moving average of three values. Sample period is still 5 seconds.

I didn't want to hold traffic up so after getting onto the A road, the first mile was done at 50, or 3000 rpm, before it shifted up and then locked up. I wouldn't normally do that to the van. After ten minutes, I was up to 8psi and mid to high 70s on the dash gauge but then it became obvious that I was still leaking pressure. Whether it's still a leak in the tank or elsewhere, I don't know, but I was happy enough watching it drop, not increase as I loaded the engine. We stopped and each had a sausage supper from the chippy, then drove home and stopped the engine. The remaining pressure leaked out.

Peter's spare header tank has not been damaged at the hands of a fool with a drill and I'll order up another few of those pressure sensors (£5 each at Farnell at the moment) and put one back onto of the bleed hose, do a run to compare the two and then replace my header tank in time for the Red Squirrel mini-meet later this month.

The block and gasket are now in better condition than they were before and I can't imagine that the use of a sealant would bring about problems in that area. I'm muddying the waters of science with my knackered old header tank, but I'll get there.

This is the 100th reply in this thread and this thread is now my new "Most active topic". I'll stop here until I can post a photo of the end result, hopefully at the Red Squirrel!

I'll continue the pressure sensing on this thread - viewtopic.php?f=3&t=56588&p=572630#p572628.

Tracking done, £35 inc VAT.

Second set of new ball joints on, all put back together. Inner ball joints on the steering rack definitely the source of noise - could hear/feel them with the wheels off the ground and giving the steering wheel a jiggle. In hindsight, should have done them while I was in there - it'll cost me tracking again, too.

its all learning eh.

The old balljoints and droplinks were definitely past their best, so I didn't do wrong to do them, but aye - learning something every step of the way. You spend to save, eh?!